I spoke to Urho on IRC, apparently Catorise is OK - it's the edit mode that hildon-desktop will get that'll break. So, the situation (AIUI) will be: No more "More..." menu, everything will be in one big long list. You'll be able to reorder that list anyway you like (through some kind of edit mode), but not create sub-folders. Catorise will continue to work the same way. Meaning if you use hildon-desktop's edit mode, it won't do anything - and it'll show you the full list of things to sort. What exactly happens when you resave out of edit mode with Catorise installed remains to be seen. I'd guess it either overwrites (until you run /opt/catorise/catorise or install a package), or rearranges things within the categories based on your order but showing you all the categories munged into one for editing. Neither sounds particularly catastrophic, TBH.