You know we've had a dozen questions exactly like this already. If you learn how to use the search function. Very useful.
Most likely yes, either Media Go will be updated to work with Vita or entirely overhauled.
Get your Portable ID!
Motorstorm 80GB Bundle w/ 320GB HDD
just bought a Vita in Tokyo Friday 17th so let me share my experience :
1) So far I managed to use my PSN European account to connect to Vita (even the japanese version)
2) however, I did not managed to transfer content I just bought from PSN Europe (i purcahsed two PSP games with media go 10mn ago)
3) not sure if this is blocked by Vita or a different Media go software, will double check
BTW, am writing a blog about it , will let you know link when published.
hope it helps