I don't think that Joss' banter/humor would lend itself well to B5. And while I agree with Tulin
that a redone B5 could better show the scope and scale of B5, I'd hope that the new show would *not* follow the BSG style of space battles. B5 gave us a feeling for the strategy of the battles while BSG gave us shakey-cam shoot-em-ups.
That said, I don't think it's anywhere near time to re-imagine B5. It's just been off the air for 10 years and is still pretty fresh in people's memories.