I hope this is "huge" for Quora, because Quora deserves success. Quora's got careful guidelines for formulating questions, along with a good socially-seeded/quality-driven reputation system, and thus far the level of its discussions has been way beyond what I've seen in most Q&A sites. It will be interesting to see whether it can survive popularity.
I just checked out some Quora topics I've been following via Bing search and don't see them returned yet.
Very smart move for Bing.