Scorching burst was, up until a few days ago, the only at-will power that was a ranged burst effect. Now that Player's Handbook 2 is out, we have a few more in the spotlight. The problem is, some think they are all mechanically superior. Are they? Let's take a look.
Call of the beast doesnt deal any damage unless the target goes after the closest of your allies. I can see in a lot of cases how it would have done this anyhow, but with a bit of setup you could potentially hamstring it. Is this better than scorching burst? I dont think so, even with the flat damage of 5 + Wisdom modifier. It also affects allies as well, so...
Chill wind is another druid at-will that deals minor cold damage with a slide 1 effect. It hits all creatures, but you do not add your Wisdom modifier to damage: its just 1d6 damage. I think that this is pretty balanced with scorching burst, since you are sacrificing damage for a very minor slide effect.
Grasping shards is an invoker at-will that deals flat Wisdom damage and slows affected targets. Again, it effects all creatures. Not to bad, I suppose, but not inherently superior since the damage is going to be pretty tame.
Vanguard's lightning is honestly the only new ranged 10, burst 1 at-will that trumps scorching burst, since it does the exact same thing but also has the potential to deal extra damage if the target takes an opportunity attack before the end of your next turn. The bonus damage is equal to your Int mod, which is a secondary stat to invokers, so I expect it to be very small (a couple of points) until much later in the game.
However, I do not think that its so much more powerful that it blows scorching burst out of the water, or that the wizard is now in need of a major overhaul. The damage is very small and highly situational. I think other things need to be factored into the equation, namely feats and magic items. A master's wand of scorching burst kicks things up a notch by adding another d6 to the poor bastard in the center of your blast, and thats a property. There might be others, but I'm going to come out and say that I dont think it needs changing, or that items and/or feats are now necessary to make the wizard playable.
If you think that scorching burst is in dire need of a kicker effect, my suggestion is to have the target take additional fire damage equal to your Dexterity or Wisdom (whichever one you think makes the most sense) modifier if it moves more than one square before the end of your next turn. Forced movement should not trigger the bonus damage.