With the recent Bitbucket redesign Github and Bitbucket are now pretty much equal in the features and looks department which makes switching that much easier. Especially if your a small studio with less than five developers the choice between free (Bitbucket for unlimited private repos) and $25/month or more (Github for only 10 repos) is an easy one to make.
Luckily switching git repositories is a simple matter of changing the upstream on the machines that use the repo which is terribly simple.
git remote rm origin #Removes old origin git remote add origin git://<repo url> #Adds new origin pointing to BitBucket git push -u origin master #Pushes commits for master to new repo
Depending on your setup you might have to change the upstream for other branches too but this is all there is to it for the basic setup.