I saw a 17 minute preview in IMAX 3D last night, and it was pretty sweet. Better than I'd hoped, at least from that small sampling. I wasn't even going to go see this in 3D initially, but now I am definitely going to do so. I haven't seen anything worth the 3D purchase since Avatar; they really got the depth and immersion so good with their remastering of this one.
Rocket had the biggest role in the snippet we saw, but everyone had their moments (including Groot, whose three-word dialogue still managed to actually showcase a range of expressions). Dave Bautista was probably the big surprise to me; his straight-man Drax was well done and had the single funniest line of the night. There was a lot of humor, but a lot of action as well, and the sets and costumes and characters all looked amazing.
Really looking forward to this one!