A dragon sorcerer in 4E can make an excellent melee class. Add in Sorcerous Blade Channeling and the fact that dragon sorcerers will have Strength scores on par with some Fighters, and the sorcerer can melee just fine. I could also have an AC high enough to make myself damn near unhittable by any same-level monster in the game--in cloth.* Melee weaons, and heavy armour? Here's where the line is crossed. Sorcerers just don't strike me as the gish class. Extra weapons sure, but not as many as they have. And while I'd buy leather, scale or plate is a bit much.
The dragon sorcerer as presented in the Next playtest seems very much like an evolution of the concept fleshed out in 4E, which, in turn, seemed like a fleshing out of the flavor text in the Sorcerer's 3E entry.
Personally, this sorcerer write-up is the most exciting thing I've seen come out of the playtest so far.