Work never ends. But I suppose that's a good thing. I'm currently plugging away on my tools for Compudigm and having a lot of fun doing it.
Group Theory is actually quite difficult. Not so much in the material that it covers but in the precision it requires. I'm always catching myself going a*b*c = b*a*c = b*(a*c) = b*n only to remember 2 hours later that the group isn't Abelian! Though a lot of people would write off group theory as useless theoretical rubbish I'm finding it very useful. The rigour it forces me to use with my logic really cleans up my programming
Nautilus just gets better and better. Not a day goes by that I don't use it. If only I was more of a programmer and could add a CVS view and a smb:// module for gnome-vfs. Then it would be truly useful. No work on LyX unfortunately, too much paid work to do.