Well to respond back, of course im not 70 yet so i don't know about arena's but i wanted to talk about my experience in bg's. WSG to be specific

I didn't die once.
It was a totally overpowered feeling. Twinks decked out in hundreds or thousand of gold worth enchants, and etc, i killed dam near most of em.
The only class i didn't try to face was paladins and warriors, i was to scared of the mail lol.

But as for the other classes, on a warlock which was completely twinked, i stealthed up to im/her and did the usual sap, Without my shadowstep (which will make it so much easier)
I dropped 2 ambushes, 2 backstabs, 3 kicks, 3 -3combo point eviscerates. He/her dropped like a ton of bricks. It was great

Since ALL my moves are one macros and 3 buttons for cast sequences. I defeated a druid and shammy easily. More stuns later will make for easier kills.
like Cheap shot, kidney shot, mace spec.

All in all my experience was a really positive one, i really think i could pull off some sort of good rating in arenas. I will be dam dedicated too.