Comment 6 for bug 635223

I can confirm that *.desktop files generated by Wine indeed don't contain a category.
It is tricky to make sure the categories do end up correctly in these files since Wine has no source to draw the information from. On top of that, you could ask yourself whether it would be desired behaviour to have Windows applications run via Wine show up in the regular categories.

Adam, if I read your patch correctly, you don't create a separate category for Wine applications, or any category-less applications, but only make sure the Wine applications are part of Unity's 'All Applications' search domain, right?
This seems like a good solution to me.

Would adding a separate category for Wine applications be an option as well? We could make Wine add a category 'Wine' to all *.desktop files it generates, and make those show up under a heading like 'Windows applications' or 'Wine'. Problem: how do we convey to a user the meaning of this separate category when a lot of people already seem to have troubles understanding that applications for Windows cannot run (natively) on Linux distributions or Mac OS?