Another thing I wanted to improve is displaying of feeds in web browser. This can be simply done by adding CSS style.
If you want to list all category feeds on main page, you can find it in my patch for generating this listing.
And last thing is enabling and fixing of title based permalinks, which was first thing I hacked for NanoBlogger :-).
Update: I filed NanoBloggers patch tracker with all those patches, let's see how much of them will get included.