Aykroyd will be voicing Yogi, and he really is the most obvious choice to play the picnic basket thief. He's funny, he sounds gruff, and if it was live-action it would be a very terrifying thing to see. So thank goodness this is being done as a CG / live-action hybrid.
Timberlake will be voicing Boo Boo. Yep. The man who wants to love your mother, put his d*ck in a box, and who will cry you a river will lend his vocal talents to playing Yogi's diminutive sidekick. In this update of the Hanna-Barbera cartoon, expect Boo Boo to be a lot more of a smart aleck. (I was going to say "sassy," but I think that would be a far different Boo Boo.)
Though Faris has done voice work before, it sounds as though she might be one of the live action elements to this unholy hybrid. Variety says she's set to play a documentary filmmaker. Presumably she discovers the tourist robbing bears, and makes a film of them. Or she has to help them preserve Jellystone against evil developers. Either way, she'll have to talk to big rubbery CG bears, and it might be kind of weird. What would be even weirder is if one or both bears fell in love with her, so let's hope she falls into the arms of whoever plays Ranger Smith. Shooting is expected to start in New Zealand next month.