Just want to give you a quick status update:
1). Onlive App works flawlessly on my Samsung Galaxy Tab 7+
2). I bought the Wireless controller, pair it via Bluetooth with my GT7+ and it works
3). I can start Onlive app, play Lego Batman (FREE if you register) and use the Wireless controller to play.
The wireless controller, once connected to Bluetooth, can even control the GT+. I use Go Launcher and I can move left and right to different screen, play music by pressing the "Play" button on the controller, etc.
So now I can play pretty much ANY games on Onlive via my GT7+. Lego batman, Just Cause 2, and HomeFront multiplayer.
One thing to note: pairing the BT requires following the instructions in here.
Once it's done, it's a breeze!