If it makes you feel any better, Mos Def has been acting professionally a lot longer than he's been rapping.
That doesn't really, no.
The main reason I'm not positive about this film is that it's so American-centric. The book is so abundantlty British in it's language, tone, humour, etc. I mean, you can't read it without adopting some faux British accent in your head.
As an American film, I just can't see it working.
O come now, how many British actors play American roles?
Hell, Batman Begins cast is almost entirely British. It's hard to find a more american film than that.
Besides, not that I care to see it or want to, but didn't people bit@h about the same thing when it can to Bridget Jones Diary ("she's the quintessential British women") and Renee "squinty" Zellweger (sp)? And by all accounts I remember, they ended up liking it.