Was finally able to spend some time with my Vita TV... Tested the following US retail game:
WORKED:
Lumines Electronic Symphony
DID NOT WORK:
Army Corps of Hell
Ridge Racer
Mortal Kombat
Wipeout 2048
Unit 13
Call of Duty Black Ops Declassified
Smart as...
LittleBigPlanet PSVita
MLB12 The Show
Super Monkey Ball Banana Blitz
Hot Shots Golf World Invatational
Gravity Rush
Any other questions, shoot! I had internet connectivity during testing but was not signed in to my Japanese PSN account. That said, each game that had patches available prompted me to download them as if I was connecting from a regular Vita. None of the above titles had patches available to me that enabled VitaTV compatibility.
Misc notes: Hardware prompted for an initial firmware update and does feature full English text in the OS. Not on PSN, though, just Japanese there. Also worth pointing out O is select and X is cancel, as is the Japanese way. Still can't get used to that!