Just that. I think it is an important feature to facilitate collaborative work.
This was reported as the wishlist bug #366271
This has been on our radar for a while now, yes. We are going to approach releasing this incrementally (ie, probably expose un-deleting files first).
I don't have a release date for versioning, but it's something we're building towards. As soon as we set a date, we'll announce.
This is planned for the future but currently Ubuntu One doesn't have this feature.
However, you should be able to do your own version control (through bzr , git etc) and sync over the version control folders alongside the other synced files. In a folder that is version controlled using bzr, all of the version control information is held in the .bzr folder within the parent folder. As long as this is synced, the version control information should sync.
I haven't tried this myself but it is probably the best solution until version control is implemented as part of Ubuntu One.