Community

I had a couple of different wizards in my mind. Summoners seemed generally weak, cold wizards seemed to be decent, and Epic Orb Wizards are just plain unfun; winning a battle with a single spell just doesn't make a fun evening. So I combined the 3, and I think it worked.
Optimized for fun (and with a pretty effective panic button too), I present you:

THE FROZEN SUMMONER

Level 30
Eladrin Wizard - Rimetongue Caller - Winter Sovereign
STR 10, CON 22, DEX 17, INT 26, WIS 15 ,CHA 13
Hitpoints: 186
Defenses: AC 45, Fort 45, Ref 47, Will 42
Items: +6 Earthroot Staff, +6 Displacer Starleather Armor, +6 Brooch of Vitality, +5 Architect's Staff, +5 Orb of Inescapable Consequences, +1 Defensive Staff, Phrenic Crown (epic), Tome of Arrest +1
Feats: Epic Fortitude, Epic Reflexes, Spell Focus, Vengeful Summoner, Arcane Mastery, Paragon Defenses, Arcane Admixture (Cold, Wall of Fire), Improved Staff of Defense, Improved Tome of Binding, Lasting Frost, Leather Armor Proficiency, Toughness, Implement Expertise, Careful Summoner, Arcane Fire, Wintertouched, Second Implement Mastery (Tome of Binding), Background (add Primordial to languages known)
Powers:
At-Will: Illusory Ambush, Scorching Burst
Encounter: Crushing Titan's Fist, Wall of Winter, Freezing Bolts, Sequestering Force
Daily: Summon Living Mountain/Greater Ice Storm, Prismatic Spray/Summon Abysmal Horde, Summon Rimefire Brute, Summon Black Devourer/Evard's Black Tentacles

"Summoned Creatures" Show

Tactics:
The frozen summoner himself doesn't like combat very much, he'll stay in the background as much as possible. He loves being invisible, sitting in a mansion or flying above the battlefield on his raven while commanding his summoned monsters do the fighting.
His standard tactic is as simple as it is effective: Put enemies in a place that hurts them, and keep them there.
He uses the Architect's Staff to summon a Wall of Fire or Wall of Winter on top of his enemies. Then, he blocks as many exits as possible (if not all) with Illusory Wall (or wall of Ice if he wanted them dead quicker). Enemies that manage to find a way out, are prevented from leaving by the Summoners allies.
If allies are unwilling to assist the Summoner's cunning plan, he creates new (and better) allies. The Chainbearer can slide enemies back into painful places (or away from the Summoner), The Black Devourer can grab enemies while himself ignoring the icy cold. Abysmal Hordes use their numbers (not to mention their triple damaging auras) to encourage enemies to stay where they are. Rimefire Brute knocks enemies prone, as does The Mountain, who also, well... just stands in the way really. Did I mention they all have a damaging aura too?
Since nearly every attack is cold, you and your pets will have constant Combat Advantage and their aura and attacks will deal extra damage too.
The summoner tries to only spend action points on regaining his daily powers with Arcane Mastery. He doesn't like to get tired.
Oh, before I forget to mention: always have a backup plan!
Plan B, which is more effective (but a lot less fun at the table):
When in trouble, pull out your Orb of Inescapable Consequences and hit (or miss, it doesn't really matter) your enemy(ies) with a chilled Prismatic Spray. They won't like it, or the -16 to the save they need to get out of that nasty stun and damage effect. Also, with a little luck, the enemy will be petrified indefinately thanks to Frozen in Ice.
Only use this in case of extreme emergency though, because let's face it, Orb Wizards are fun for a theoretical build, but noone wanted to win the game in a single round... just know that you can should you need to.

"Level 1" Show
"Level 2-10" Show
"Level 11" Show
"Level 12-20" Show
"Level 21" Show
"Level 22-30" Show

Q: Wait, you're summoning with a Tome while wielding an Earthroot Staff in one hand and a Defensive Staff in the other? (And other implement-related issues.)
A: Thanks to mage hand, it's only a minor action to switch implements. The only reason we actually want a Tome is because of the damage bonus your summon gets from Tome of Binding. The summoning spells are minor actions and are ranged so can be put right next to the enemy, spend a move(changed to minor) action to stuff the Tome in your backpack and get something that's actually useful and you still have a standard action left to command the attack.

Please comment, please be polite. (This is the first complete build I post, all fixes and pointers to make things shinier are welcomed.)

Spell Focus is from PHB, the -2 to enemy saves feat. Req 13 Cha, which is why I boost Cha at 24 instead of Con.
Rimetongue Caller is a wizard PP from Arcane Power... Damn it! It requires primordial as language, that'll probably be the problem.
Any background feats that add a/primordial language? Don't have any feat slots left.

Great, thanks!
Strange though, the ED requires you to be a fey race and describes you as a Winter Lord of the Feywild... so obviously some Eladrins are meant to have close connections to the elemental forces.
I guess I'll just add something generic like "background feat that gives you primordial as bonus language".

Does the character builder say anything about the summons?
This build is pretty much based on thinking/hoping that Arcane Admixture or Winter's Bite change their attacks to cold and that this works for giving CA versus enemies given Vulnerability with their attacks.

I really like this build. I am even considering playing something similar in my next game, since it seems to be much more fun than your typical Orbizard.

I have a few questions, though.

He loves being invisible, sitting in a mansion or flying above the battlefield on his raven while commanding his summoned monsters do the fighting.

Are you sure attacks from summoned creatures don't count as attacks from you for the purposes of Greater Invisibility or Summon Diamond Falcon? After all, you are making the attack rolls using your bonuses. I am asking because I honestly don't know, and could see a DM ruling either way.

STR 8, CON 15, DEX 15, INT 18, WIS 13 ,CHA 10

Why start with DEX 15? I know it is very efficient point-buy wise to buy dex up to 13 and then add the +2 from Eladrin. However, this build doesn't really use the extra Dexterity at all. Starting with Dex 13 would be sufficient to meet the requirements for Wizard implement Expertise by Epic.

On the other hand, you might want to spend feats to utilize this Dex instead. Maybe pick up Arcane Reach, Dual Implement Spellcaster, Quick Draw, or Seize the Moment?

A: Thanks to mage hand, it's only a minor action to switch implements. The only reason we actually want a Tome is because of the damage bonus your summon gets from Tome of Binding. The summoning spells are minor actions and are ranged so can be put right next to the enemy, spend a move(changed to minor) action to stuff the Tome in your backpack and get something that's actually useful and you still have a standard action left to command the attack.

While I agree with the above, I still think the limitation on the number of actions you can take in a round would be the biggest problem with this build (and Summoner builds in general). It seems like it would be especially bad if you are sustaining one or more Wall spells and have to summon another creature.

Mordenkainen's Lucubration might be a good Utility spell to pick up if sustaining spells turns out to be an issue in combat.

It might be a good idea to pick up additional ways to quickly retrieve items if you have to keep switching implements on the fly. Perhaps Quick Draw, Battle Harness Armor, or probably best of all, Arcane Familiar (disembodied hand/rakshasa claw).

I know this is easier said than done though. You are pretty tight on feats as it is. I am personally not the biggest fan of Vengeful Summoner. That said, I am not sure how often summoned creatures actually die in practice, so it may be more useful than I think.