Whatever one thinks of Facebook, the two interfaces aren't equivalent and just having one won't give you the other. Especially, "Micro-blogging" doesn't give structured, moderated discussion of any kind.
And well, I personally think in the social network world, a large portion of Twitter is a pox on humanity, not by its control by particular entities but by the interface effectively working to elicit and amplify shallow, reactive, emotional responses.
The Facebook interface has its problem too but it's structure is more ambiguous, you can get "deeper" discussion are restrict who's talking and moderate well. And you moderate feed as well as groups, on Facebook itself.
Personally again, what I'd like to see is Twitter dying and Facebook being cloned by a better peer-to-peer. But in any case, just cloning Twitter wouldn't give you a Facebook competitor.