For me and where I work, GitHub's repo restrictions are the one and only cause of us self-hosting a Git server instead of using them. We have around a hundred small, low-traffic repos.
Let's put it this way:
* on GitHub, thanks to our repo count, we would be a $200/mo Platinum account
* on Bitbucket, thanks to our user count, we would be a $0/mo Free account, although we might have to upgrade all the way up to a $10/mo account as we're adding some people.
Needless to say, I will be looking hard at Bitbucket now that they're supporting Git.
I guess this answers your question. I'm a happy Github customer myself (both personally as well as with my company), but it is interesting to see Bitbucket compete with them head-on. I can see quite a lot of small/medium companies move over.
Let's put it this way:
* on GitHub, thanks to our repo count, we would be a $200/mo Platinum account
* on Bitbucket, thanks to our user count, we would be a $0/mo Free account, although we might have to upgrade all the way up to a $10/mo account as we're adding some people.
Needless to say, I will be looking hard at Bitbucket now that they're supporting Git.