The Vita to me is exactly like the PSP. It had few must have games for me, but in time I'm sure it will. I only recently got a PSP, but definitely was a good buy, as I'm sure the Vita will be in time for me as well. Unless the rumors of some developers switching to the 3DS are true.
And while I think giving people a 10% discount for buying games digitally is nice, games like Uncharted are about 5 gigs, and I'm sure there will be larger games. If you download that title you better be buying a big memory stick, and would you really end up saving money in the long run? Maybe if you went Jesswee's route and swapped games on and off.
I see it going very similar to the 3DS though, but maybe not as well as the 3DS is now. And yes, the 3DS has actually become the fast selling console in Japan, ever. graph.gif