I know slackware supports ARM. Does that mean it can run? I've heard that slackware might not run on the pi.
Out of the gate I'm sure it won't run. There are just enough differences between ARM chips to cause small roadblocks. That being said I'm sure someone will make it happen, and I don't imagine it will be hard. There has been some interest in making it work so someone will make it happen in due time.
Edit: Also like most of these questions of this nature they should be asked to the people working on the distro...