XG had a pro team in 06 that made top8 a few times. They were disbanded before too long though because they started getting better sponsorship offers from other people. There've been a few teams made up of people from XG go to events since then, some of which placed fairly well, but there haven't been any official representatives since.
There's also a branch for competitive players in XGC if you're interested in trying out. It's the 'XGC Elites' - they take the best 36 players in XGC and divide them up into three strings. First string is the best, second is second best, third is third best. There're twelve players per string, making up three teams. You could try going there if you want to find some good people to team with.
Here's a link to their section of the forums:
http://www.xiledgaming.com/forum/forumdisplay.php?f=2935
