I'm a huge fan, though if they do it like 4E, shove naughty word in that doesn't belong (e.g. tieflings, dragonborn) and lazily reskin material (goliaths = half-giants), I'll run my homebrew conversion instead.
I'm not hopeful we'll see a full commitment to a Dark Sun line, or any other line. And here's why: Brand Dilution. TSR ran itself into the ground by not understanding the market. WOTC has a very good understanding of the market. It's what allowed them to buy up their ailing competitor eventually. And that understanding is that Brand Dilution means the more product you put out for alternate settings, the worse off you are. A Dark Sun player won't buy your latest Realms adventure, or Book of Goblins, because it's useless to their favored setting. Under this model, the more you diversify your line with new settings, the more you shoot yourself in the foot, and this was true for TSR. Since WOTC bought TSR after seeing this firsthand, I think they'll be gun-shy doing what TSR was doing.
So, if WOTC is following this principle, I don't expect to see much innovation, just a half-assed adaptation to plug-and-play with material we already have. I wish they'd be bold at a risk to their bottom line, but when I'm disappointed I'll understand why it had to happen the way it happened.