I've been working on adding feed categories into Straw for the last two weeks or so. Well, for a few evenings during the last two weeks.
I first attacked the problem with the traditional(?) hierachy. We have a tree widget for the feeds anyway, so it was just a question of adding the hierarchy. I got pretty far with it, it displayed the hierachy, you could open and close branches and it would remember their status, and you could drag things around (this thread was immensely helpful when hacking on the d'n'd stuff.) At least it mostly worked for me, even though I heard some conflicting reports :-)
Naturally by the next morning I had in the back of my head a different approach to the problem. I've never much liked navigating tree views — yes I'd love to see a column view in Nautilus — and hierachies are a bit restricting, aren't they?
Savannah being sort of dead at the moment has put bit of a damper on progress, but still, it's starting to look sort of working, even though it'll still need quite a bit of love before 0.22. There are still things broken, unfinished, or working non-intuitively, but the categories are sort of