Yeah, I'm already feeling this, and I only got a few PSP games on my memory stick.
The thing I was talking about with a friend of mine though, because he was looking to go mostly digital with the Vita. Cheaper price, and less hassle to switch games. However looking at some of the sizes of the games, I feel like it wouldn't be long at all before even a 32GB would seem like not enough space. Games like Uncharted, and Blazblue are already over 3GB each. Even if I had a 32GB card myself, I would be hesitant to buy either of those games digitally.
I have no desire to go fully digital - with sales, specials, etc., I can flesh out my library for the same cost/cheaper. And realistically, and decent case will be able to hold 4+ games. The thing I want to do, though, is be able to store more PSN games. Between Gods Eater Burst, MJ The Experience (thanks Ubisoft), and save data, I've only got 1288 MB left. I don't think that's enough for DJ Max 3 or MHFU, so that's a bust. I can toss FF for PS1 on here, which is cool, but not exactly what I wanted.
Anyways, digital is great and all, but we'd need a 3rd part 64gb card before that would be viable I imagine.
Also, I just found a $5 reward that I have on my Best Buy account. Time to go buy something.