I can understand "why" they will do this
as I wrote elsewhere, I can understand why they would charge for the digital copy. The PSP games didn't require any kind of serial number for you to be able to play them, and each disc is not uniquely identifiable. So to stop everyone from _sharing_ their PSP games with everyone else, this is the only alternative. (note, nothing is stopping the gamer from sharing the game anyway or selling it after getting the digital copy).
My biggest concern is, what about the people that imported Japanese games, how will we get the digital copy? Those games are not available in the US of EU PSN, and creating a Japanese PSN account for the sake of getting those games doesn't sound practical. Plus, the PSP suffered from a simple flaw, it did not support multiple accounts, so gamers had to find a Wi-Fi or use MediaGo to switch between accounts if they want to play a game from another region. If the PS Vita suffer from the same flaw, this would be problematic for people like me.
Any way, I -for one- won't be throwing away my PSP just because I got the PS Vita, heck, I am thinking of getting the PSP-E to replace my -still good- 2 years old PSP-3000. So beyond worrying about how to get the digital edition of my Japanese imports, I am happy.
P.S. It wouldn't surprise me in the slightest if Sony announce -few month after launching the PS Vita- they they sold more discounted _digital_ copies when compared to the actual UMDs sold.
forgive my EngRish