I was asking if one was currently in existence. I guess not.
All currently available importers can be found in the members area, these include:
PHPBB
UBB.Classic 6.7.x
UBB.Threads 6.5.x
Rick has stated that he's planning on working on more importers after the release of UBB.Threads 7.1 which is currently in Public Beta release 4.