Yeah, I play on a 57 human warlock, and yes, I own in PvP even though I'm demon specced
I should be 60 in a few weeks, at least before BC.
As for summoning, I normally just ignore someone unless they have a group where they are wanting me to summon them. Last time I summoned someone, I summoned a lvl 2 human warrior to the Barrens because he wanted to go to Darn. Sorry, but lazy people bugging me to waste my time is annoying, but I still don't normally charge when I DO summon.
As for Rogues, as long as they don't have a party of 2 or more with them they are worm meat. Even if they do have a few comrades, as long as I don't get charged from a warrior, silenced, or surprised with a kidney shot, it's not a problem.
Shadow priests aren't a problem for me either. Shadow Ward FTW. As of right now, the only classes I have problems with are Marks hunters with Silence, or Mages who understand how to play their class. Doesn't mean I lost to them, just means I actually get a little hurt. Soul Link pwns you.
I just posted my CT profile, which is 1 lvl outdated (I still put that I was 57, but didn't update skills), but here ya go.
http://ctprofiles.net/4181214