Bump! Since I've now finally upgraded (I stuck on 2.x for a long time, now on 5.x latest and greatest), I've spotted the warnings that image galleries are being deprecated and that file galleries should be used instead. So a content converter would be great.
Even better, one that takes Tiki Pages, Blog Posts and Forum posts to correct URL References to them.
If somebody has one, I'd love to find it. Alternatively, I may find time (not this month) to build one with a technology of my choosing.