As of 0.9.4, when adding a symbolic link Mercurial keeps track of the link itself, and not the file or directories it points to. However, there are cases when it is desirabl
I don't think there's a way to do this when you're working with directories.
If you're working with mercurial 1.3 or later you could try using the new subrepo support, that will let you have a repo track stuff ourside of it on the local disk, but it's not as seamless as a link would have been.