A simple yes or no would be good enough.
Recently, I've tried to convert an old vBulletin theme I really loved into XenForo (almost there). And I also have another theme for IPB as well.
When you get right down to it, they're nothing more than instructive xml files with some photos.
How interested would anyone be in a converter that would "guide" ....Not complete (maybe partly)... But put you on the right path... That could help you convert a vBulletin or IPB skins into XenForo skins?