The PlayStation Vita is out next week, on February 22. Yes, technically it's out as of earlier this week, but that's only for people who ordered the First Edition bundle. Next week, everyone can get their piece of the pie. Sony has a new Vita FAQ up on PlayStation Blog to get you prepped, and one of the Qs addressed reveals that "PlayStation does not have plans to make PS Vita compatible with PS3 or PS2 titles at this point."
The reasoning behind this should be fairly obvious, even if Sony never admits it: if games from those platforms are made to simply work with the Vita, how will anyone ever release Vita-tweaked "remakes" for them? Duh, guys. Seriously. PSOne support is coming, though there's nothing to reveal yet on that front. Sony pledges to announce further details "when they are ready."
Stop looking at me like that. I know this is minor news. What do you want? Friday's off to a slow start.
Source: PlayStation Blog