I pretty much agree with Bishop, i'd rather have a stated minimum dps or whatever than join a pug which is free and is typically made of poorly experienced or geared players. I was doing 2000 dps without getting a single naxx10/25 drop in 10 mans (hunter). Granted it was a royal pain to get all that non-raid gear, but doable. Point being that a 2000 dps minimum is doable without naxx with most classes (think of the group buffs, stat foods, etc).

Naxx clears take a long time, and if you have guys constantly dying or way undergeared, then you are just not going to get anywhere. I've been in epic 7 hour naxx runs, and I never want to do it again (granted I got 6 upgrades that night/morning).

Lastly, the link to epic achievements is of course overkill, but its better than saying 'dps you need 2000dps, but we'll take whatever class can heal or tank, regardless of their gear'. At least it is fair. Many times pugs fail because the healers/tanks have no idea what they are doing, while the dps, who were screened carefully, were on the ball.