First of all, the makers of Eternal Eden, an RPGMaker game, have been working on a 3DS remake for quite a while. I've had it in my head that the 3DS is therefore conducive to indie efforts.http://www.blossomsoft.com/gamezopher/category/eternal-eden-3ds/
The 3DS makes DS games blurry, and picking up an older, cheaper DSi after holding the spanking new, wallet-draining 3DS puts a negative spin on the experience. It's lose-lose. Remember those magnifiers they used to make for handhelds? That would be perfect for the 3DS playing DS games in their native resolution.
3D on a handheld doesn't have to be a gimmick, but when it is, I still welcome it. Whatever minor 3D effect Devil Survivor OC has won't anger me just because "the 3D is dumb". More to the point, Pilotwings 3D is difficult with the 3D effect off, because you can't judge your distance from rings as well.
The poor implementation of 3D in media has created this idea that all 3D is a waste of money and stupid. The 3DS is like looking at a regular DS, except there is unobstructive 3D depth. It's nice.
I hate when I draw such obvious lines in the sand, but really, how uncomfortable will it be to use a touchscreen on the back of a Vita? That's what I call gimmicky. The thing might as well have been a giant button you can tap, because that's as far as I see most developers going with that. I could be very wrong though.
Having said that, I kinda want a Vita to play PSP games. I'm assuming the battery heat and noise and stuff will be better than with PSP.