Just something to note: Split-screen multiplayer is used in all three current platforms successfully. Considering this means there's more than one camera used at once running on a single console, I'd imagine the process to create a 3D game would likely be similar, so it wouldn't be a matter as much importance, Deg.
That said, I do think 3D is rather "gimmicky." I'll say I haven't seen Avatar in 3D when I say this, but I've seen Up, as well as numerous other 3D shows at various themeparks. Remember that things have been broadcast in 3D for some time now, and it's never really caught on.
From what I've seen, it hasn't been a feature that's worth paying any extra from, nor is it worth even having to wear uncomfortable glasses the whole time. That said, I've been impressed with tricks utilizing perspective, but unfortunately, every time I've seen said things, they've required the viewer to be at a specific place, unless they measure the viewer's location, like what we've seen using the Wii-Remotes for head tracking. That technology is a bit different than 3D used now, and I believe it has much more practical application for gaming. The great thing? 3D glasses wouldn't even be necessary, nor would someone with a disability have trouble seeing the image.