A few things I noticed:

1. When entering my roommate's GamerTag, XBerry Live! indicates that it is an invalid tag for some reason. Won't let me add it.
2. As a result of point #1, when I hit the escape button to back out to the main screen of XBerry Live!, I get the Save/Discard/Cancel dialog. Not sure why?
3. My recommendation for the icon, as noted in the post above.

Other than these three issues, and I hesitate to call them issues, really, this program is fantastic. Great job!