Hmm, it looks like Misago defaults to a "flat style" now instead of the good old Categories View. I don't seem to be able to find an option in my profile settings to change my preferences here. Mind to add such an option?
I, personally, find a "flat style" board horrible to use because in most cases 9 out of 10 categories are irrelevant to me, so the flat "what's new" view is not really useful. :)