Hey, remember the "leaked footage" of the Xbox Live avatar golf game? Mystery solved. It's available on the Marketplace in the Indie Games channel. Avatar Golf is its name, because, well, it's golfing with your avatar.
It's definitely a character-swap game for Easy Golf, as some guessed when the footage was released. The good news is that Easy Golf, by Barkers Crest Studio was a pretty damn fully featured game for an indie download, including six courses and a course editor. Avatar Golf adds a multiplayer mode that accommodates eight players, and friends can join a round in progress. There are customisable weather effects and backgrounds. And, of course, you get to play as your avatar. It's 400 Microsoft points.
Playing it myself, the terrain effects are not terribly sophisticated and putting is a little too much on the easy side. Then again, this is a much more casual version of golf, designed to be played among friends.
The trial version is timed, so you'll be able to play a few holes before the game asks for an unlock.
Indie Games Featuring Avatars [360 Avatar, thanks Jim M.]