Rogues, Shamans, and Warlocks have some pretty big weaknesses as tanks. Where do we think they're going to really struggle?
Obviously Rogue is just dead weight on any multi-target fight.
Apparently warlocks ST threat gen is going to be pretty bad, but they'll shine on fights that deal heavy magic damage. Not sure if one will ever outweigh the other, though.
Returning to this thread, no fights suck for Shaman Tanks. Shaman Tank is so incredibly strong that you can solo tank the entire BFD. Loving it.