I've been running a priest/hunters group for about a year now and hit 80 a few months back. After the 3.08 hunter nerfs, heroic dungeons will require a ton of skill or superior gear to complete with that group. The pets (even tenacity) simply go down too fast on boss mobs. For trash, or pre-80, it's a terrific team and a lot of fun. It's great for dailies and/or farming, too, so not a complete waste of time to level. However, if you're looking for a path through heroics, hunters need some tanking help. I'm currently working on a Pally to tank for the priest and 3 hunters, which I'm hopeful will work better.