Yeah, I don't know. I wasn't impressed with the blaster wizard until you had AP and PHB2 to give you some added options. It certainly gets better at higher levels.
Oh, yeah. That character went from fun to broken post-AP at 11th level.
I think it is a weak option at 1-10. It isn't that some of the direct damage powers aren't decent powers, you just NEED a lot of little control effects so you have the right one for the right time and can keep wrong-footing the enemy consistently.
Nod. I had a few. Ray of Frost, because that was the other only at-will the previous wizard didn't take (darn humans), Color Spray, and the various dailies, of course (oh, I /took/ Fireball, but didn't prep it often - used it /once/, albeit well).
Personally I put AoE type stuff pretty much on the control side, but yeah now and then you WILL do good damage with it, and the implied threat is nice. The thing that was tough was you had things like Scorching Burst that didn't do ANY control.
Except that AoE control, of course. Someone - not sure if it was in this thread - mentioned the Goblin Hexer and his nasty vexing cloud. That group went up against it 3 times. The first, in the first campaign, it was pretty aweful, Hobgoblins formed up in a tight phalanx inside the cloud, very hard to hit. In order to Thunder Wave them, our wizard would have had to go into the cloud (not to mention risk being beaten on by soldiers), after using Icy Terrain and Shock Sphere she was out of 'punish them for being grouped up' powers. Second time, second campaign, similar scenario, Scorching Burst damage added up pretty fast (compared to melee types missing on a 15) on the phalanxing hobgoblins, who's AC bonus and concealment & attack penalty from the cloud meant nothing to the wizard standing 10 squares away, pounding on REF.