The card format isn't going to change at this point. They just need to get the prices down as much as they can.
I've never had a problem with the screen at all. It works perfectly on my Vita and is very responsive. Every game I've played looks nifty. I also have no problem with the sticks, they work very well. I never find myself thinking, "these are too small." I have the white Vita, so no comment about the gloss on the black.
Honestly, I'm trying to think of reasons to have a second model but I really can't. Maybe improve the start/select buttons, those are kind of annoying. Really, though, it's the best piece of gaming hardware that I've ever used. My PS3 feels so out-dated in comparison. The memory card prices are really the only thing that bug me.
Oh, and I do wish there were more apps. An eReader, for example. That's nothing that calls for a new model, however.