It's going to be really interesting to see if Community creator Dan Harmon can save the sitcom and make it good again. He wasn't involved with the fourth season at all, and the show suffered. He's back for season five though, and I really hope he can breath life back into it.
Joel McHale previously said that Harmon is “basically calling it a re-pilot of the show, where he’s re-establishing all the characters and grounding (them).” And in case you haven't heard, Chevy Chase has left the show, and Donald Glover will only be in the first few episodes. John Oliver is returning, and he has this to say in an interview with USA Today,
"Professor Duncan has such a vibrant relationship with alcohol that it’s entirely possible he simply blacked out two seasons ago, and doesn’t realize that he’s missed anything. The truth is that there’s actually a fantastic explanation for his absence that makes simultaneously complete sense, as well as no sense whatsoever."
This teaser trailer is almost cut like a trailer for a movie, and it has a very different look and feel than anything we've seen from the show in the past. This is a good thing! I like what I see, and I'm excited for the return of the series!