Any guild that doesn't understand the importance of cooperation between ALL classes is fucking retarded. Granted rogues can do mass dps, but we can't kite and when we get hit we're like wet paper bags.
If the rogues are good, then everythign runs fuckign smooth. There is not reason for a rogue to ever pull aggro off the MT (unless the tank is completely retarded, and doesn't sunder etc).
No class is more important then others. Period. A priest can heal himself all he wants, but he can't kill shit if he has too, warrior can tank, but if they're prot specced, then they can't kill shit. Rogue can dps, but one ore two hits from golemagg and down we go.