I remember doing a 5v5 team with some guild folk shortly after hitting 70. My gear was terrible, and since I'm a sustained damage (rather than burst damage) spec I didn't do well. And natch, since I'm a 'lock I was focus fired pretty heavily.

Despite that, I had a great time, and it took very little time to get the 10 rounds in. Mostly because we were thoroughly 'pwned'. My gear's better now, but it could always improve; so I'd be up for some arena action, as long as whomever I'm with doesn't mind losing 10 games ;)