I'm really disappointed with the insistence that Sorcerer will be just another arcane controller.
If you look at the (admittedly brief) history of the sorcerer in D&D, it's a class that had fluff indicating that its powers were derived from a natural connection to magic and the elements, often suggested as derived through a bloodline.
Further, as sorcerers had a more limited spell selection, and initially had to choose spells that were more or less useful throughout their careers (and even later you could only swap out a few spells at a time), the class lent itself well to specialized builds and themes - the touch attack specialist, the ray specialist, the summoner, and so on. Taking out those builds that could and probably will be a class in their own right in 4e (summoner, illusionist, necromancer, etc), you're left with a lot of sorcerer builds and concepts that depended on direct damage (and often a lot of single target spells.)
It seems to me that they're ignoring a lot of the sorcerer's past in D&D (intrinsic spellcasting, perhaps through a primal or elemental connection, focused builds, often focused on damage) in order to highlight perhaps the most lackluster aspect of the sorcerer's past - "just like the wizard, but different!"
It doesn't make a whole lot of sense to me, and seems like a gigantic waste of potential. Honestly, I think the class fit better when we thought it would be an Elemental or Primal Striker.
One year out from the edition's release, isn't it a bit early for 4e to start featuring "just like X, but different fluff" classes? Especially given that there are so many other classes that people want to see or "need" to convert their campaigns to 4e.
There's a bizarre duality to WotC's willingness to sacrifice sacred cows: they'll get rid of the substance of a sacred cow, changing rules mechanics, leaving certain elements of the game out entirely, redefining the way something works mechanically. But then, they try to force every concept back into old names and categories. Why on Earth would you do that?
I don't know... out of everything I've seen - released or announced - I think this decision is the one I despise the most. And there isn't a whole lot that I dislike. But this one thing just annoys me to no end.
Edit: The other issue with the "just like the wizard - but different!" approach is that there's no longer a mechanical need for that. In 3e, it filled a gap for people that wanted somewhat less Vancian concepts in their arcane spellcasters, who didn't have to rely on a spellbook and technically didn't "forget" spells once they cast them, someone that didn't have to spend a lot of time fiddling around with which spells they would memorize that day. Almost all of that need is gone now in 4e. (50% gone, counting utilities and dailies, and that remaining 50% is watered down - all classes have to have once/day powers, even a proposed sorcerer class.) Leaving the sorcerer with nothing but the fluff, and the common uses and builds for the class, which do not lend themselves to being another arcane controller.
Of the one Vancian aspect left to Wizards - picking from one of two dailies or utilities each day, one of three with a feat - I'm also really concerned with what they'll come up with to compete with that from another arcane controller that won't be ridiculously overpowered or potentially game breaking. One of the major remaining appeals of the wizard is the ability to change utility and daily powers every day, from two or (quite easily) three choices, whereas everyone else gets one. To make a sorcerer an arcane controller that is a valid and desirable choice compared to the wizard, they're going to have to offer up something really good. Probably too good.