A rogue - druid combo would be nasty in pvp. I have a druid that's spec'd mainly feral, has max stealth, and has feline swiftness, and I have no problem keeping up with friendly rogues while stealthed. Druids also get track humanoid while in cat form. Having someone that can stealth with you that has decent dps in cat form, heals, rez when needed, provides mark of the wild buff (which has +resists at higher lvls), roots, can put hunter pets to sleep, and that has a decent ranged attack, I'd vote for that
Edited: forgot to mention that druids in cheetah form can chase most classes down that don't have mounts.