Just trying now on my HTC Desire:
Sign in is straightforward, friends are listed in a mad order, those online you have to dig for.
Have to touch a name to see what they are playing, only after fetching in this way does it show on the friends list - how daft - other 3rd party apps to a better job.
The build in game browser is good to quickly dial up games info for your pub discussions I guess. Yeah I have Google for that don't I?
There is nothing special about this, but it's slick. Lets hope they give it a bit of welly, adding messaging would render it almost useful.