I'm not sure this exactly addresses your issue, but BitBucket very recently released a concept called "projects" for grouping repositories.

https://confluence.atlassian.com/bitbucket/projects-79249795...

Unfortunately, it's only for teams right now, it seems. Additionally, (and this may only be a me concern) you can't include repos in more than one project, like in the case that you have a common framework you build between separate projects. I mentioned this to them (may have even had a support request), but haven't gotten any feedback.

Basically, it's much more rigid that I personally find useful, but it seems like their first step in the right direction.

[Edit] Seems kannonboy said the same thing, but I'll leave my opinions here. Interested to see if anyone else has used it and has any opinions.