I just posted about the Season 3 DVD release of It's Always Sunny in Philadelphia because it was the funniest one yet. And now FX is running ads saying the show will return for Season 4 on Thursday, September 18th at 10 (I'd assume that's Eastern Time). Booyah! It was never really official, and I hadn't seen a concrete date anywhere before now.

In case you're behind, hulu is streaming a lot of episodes for free.