Try the West wing of Dire Maul Seb.
We meandered past a fair bit of it as I was mainly after my level 60 water quest (yay!) but the mobs in there will be a good test for a 5 man group.
That is of course assuming you can get into the insstance at all, gank central last night as every 60 and his dog was in Ferelas trying out the new content
[edit] Oh, and did Rend drop anything different that you noticed? i.e if I see those frikken shoulders one more time.....