The thing with digital only releases, is they can lead to being a self fulfilling prophecy with the fact that "we don't think there's demand to justify physical so we'll do digital only" then "everyone is happy with digital, we won't bother with physical at all"
That would be bad for Vita because it would give it no retail presence at all. Though it could well mean VitaGo redesigned console would be a lot more viable than the (IMO awesome!) PSPGo was.
In fact, the only problem I had with PSPGo, was that half the games didn't get released on PSN meaning I had the console, but couldn't get the game. Funny how Vita is getting the polar opposite.