Ok, I have some more time so here goes the warlock, warlord, and wizard analysis.
*Warlock*
Curse of the Golden Mist / D
Fireswarm / C-
Tendrils of Thuban / B-
Thirsting Maw / C
Curse of the Golden Mist is simply a waste. You are using one of your precious dailies, not to do damage, but simply to trade your actions for the targets. This is most useful on solos, the very monsters where you are most likely to miss with this power. If you don't believe me, imagine that this power was "Hit: Target is stunned (save ends)" That is weak for a level 15 daily but better than this power.
Fireswarm is another sustain standard power which becomes worse the more powers you have and better options for your standard action become available. The damage is good but NPCs can easily avoid the splash damage on the later turns.
Tendrils of Thuban is only halfway decent because how difficult it is to get out of the zone once the NPC is stuck in it. Since the NPC saves at the end of its turn, it leaves itself open for being immobilized again by the power's continued effect.
Thirsting Maw does low damage coinciding it is a level 15 daily. There might be some use for it considering the new warlock feats that let you deal damage to yourself in exchange for benefits but I don't know those feats well enough to comment.
*Warlord*
Make Them Bleed / B (D if the ongoing damage doesn't stack)
Renew the Troops / B+
Warlord's Gambit / C
Make Them Bleed adds 5 ongoing untyped damage which I don't know if it stacks or not. I know ongoing damage from the same source does not stack, if a monster hits you for 5 ongoing fire damage and then hits you again the damage does not become 10 ongoing. I'm not sure if that applies to this power or not. Anyone have a good grasp on the ongoing damage rules?
Renew the Troops heals without using a healing surge which is quite handy in a pinch. You're rarely going to be able to use this to heal everyone because damage is usually concentrated on 1-2 PCs but every bit helps.
Warlord's Gambit has the nasty problem of giving your opponent choices. If it's beneficial to hit you, the NPC is going to enjoy the attack bonuses and if its not then the effect is wasted. The penalty of having an ally make a basic attack against it is not that prohibitive as its roughly the same as a fighter's mark which monsters ignore if the benefits are high enough.
*Wizard*
This is the level that wizards start to really play with the good spells. Up to now, their dailies have been not that interesting but from now on wizards get spells that really control the battlefield.
Bigby's Grasping Hands / B-
Blast of Cold / C
Otilukes Resilient Sphere / B
Prismatic Beams / B+
Wall of Ice / A
Bigby's Grasping Hands deserves extra points just for its humorous nature. Sadly the fact that it needs a minor action to sustain means that it competes with other cool wizard powers.
Blast of Cold. Remember buring hands, thunderwave, color spray, thunderlance? If you do, then you already know Blast of Cold, the latest and not the greatest in the series of close blast powers that do damage and a minor status effect.
Otilukes Resilient Sphere is excellent for isolating a dangerous foe for several rounds while the rest of the party cleans of the rest of the NPCs. The only problem is that you need to hit on that attack roll as the miss effect is nothing to write home about.
Prismatic Beams is amazing if you roll high. If all three beams hit which will happen more often the only some of them hitting, the target takes 4d6 + 2 INT, 10 ongoing and is dazed. Dazed is one of the nasty status effects to inflict and it is keyed off the lowest defense.
Wall of Ice is what you have all been waiting for. A wall 12 can completely surround two adjacent squares. It does 4d6 to each creature attempting to break the wall down and doesn't even require an attack roll. Aside from blade cascade, I'd say this is the most powerful level 15 daily.
Ok, that's it for the level 15 dailies. Now for the fun part where you the reader tell me where I'm wrong. It's pretty unlikely that I've managed to get everything rated accurately so don't be shy and tell me which powers I've underrated and which ones aren't quite as nifty as I thought they were.