Make it OpenSource
bitbucket is great. But wouldnt it be greater, if it were OpenSource? On a developer platform are - of course - a lot of developers, who could help coding bitbucket.
So: Why is bitbucket ClosedSourceSoftware? rms would ask you, whether there is any "virus" or sth. like that here. I do not think so, but I cannot find any reasons for unfree software here.