It would be nice to have the option of importing code from an outside repository as just a set of files, without the branches, history, etc. It would be the equivalent of (but faster and easier than) checking out a repository to a local computer, creating a new repository on Bitbucket, and then checking in the individual files.
If the repository is just being created to have a place to save local patches, the external history is just noise. And it would have the side effect of allowing the conversion between different repository types.
Suggested: Add an option to the "Old Repository" portion of the repo/import page similar to "Import Full Repository History" that defaults to yes.