Depends on how you stat, really. I've seen some successful tank builds on DPS classes that do quite well in SW like this one :
http://www.youtube.com/watch?v=XBinvIyXK6Y Its just that most people opt for straight glass cannon build.
Thats an excellent point. Knights can do well in pvp just because of how much damage they can soak up before croaking. Ofcourse, your rotation with knight is everything and messing that up will result is a very fast death(in knight scales which is still about 5-8 secs normaly). Certain class combos are better built for pvp than others, but all classes combos have their strs/weakness.
One class/combo that is over looked a lot is d/m. It can do some nice damage(1sec cast earth arrows) with alright crowd controll. It can heal/res others. And, most rogues and meele guys completly forget about rocks protection which makes you pretty much immune to meele for 5 secs with a extra sec of lag time. Speaking of which, I will be moving on from my knights untill they get fixed and most likly go back to my d/m/wd.
I will, at some point, publish a knights pvp guid. It will not include stating because that is upto combo and play style. as for skill rotation, I have one for every combo of knight and how to use them on every combo in game. Problem with knight is, dont play one main to lvl with.
Have fun all,
Soul