git annex import DIR/* will import all the files in DIR, both those that are already known to git-annex and those that are new. Using the option
--skip-duplicates one can import only new files that are in DIR but unknown to git-annex.
It would be nice if there were an opposite
--only-duplicates option that could be used to import only the files that are already known to git, ignoring the new files in DIR.
PS: it would also be nice to have aliases like