What's up with the 3D craze these days?
It's a way for studios to cover for shoddy writing and mediocre acting. It's also something that is(at least for the moment) solely available in theaters or to people with bleeding edge home theater systems. It's also something that is extremely difficult to pirate
writing and acting: the guild strike was an unmitigated disaster, and due to the time frame involved in producing a big-budget film, we should just now be seeing fully post-strike screenplays. and as far as acting? we haven't had a really bankable leading man/woman since tom cruise lost his mind. pitt and damon are past their prime, same with clooney. daniel craig had a chance with the bond roles(almost always a good springboard) but the studios finances went in the toilet depriving him of a vehicle. and the writing has sucked, making chicken salad from chickensh*t will get you recognition, but chicken salad won't get you fame.
tech: this is big, theaters were in a great chance of dieing off, home systems were too good, dvd/blu-ray were too available. there was, some would say is, no reason to spend gas/time and get gouged on concessions for the "theater experience" since the experience wasn't all that much better than home. thankfully this is temporary, 3d home systems are already available, and like hd will slowly percolate through the marketplace and theaters will have to find a new gimmick
piracy: this was BS, but it's one of the worst kinds. studios started to believe their own spin. they felt that they needed something to combat the fact that every movie is available online within a week and latched on to 3d for its technical difficulties. again temporary, 3d capable graphics cards entered the market around the same time as 3d televisions. they do have an advantage that most of the tried and true methods for getting a 0-day movie digitized won't pick up 3d. the 3d dvd market is screwed however.