I think that the less there is to get in your way the better... hover or click toggles in the corner pixels to pull up bars or menus when you need them and put them away when you are done are great. This follows fitt's law nicely... and a nice thing to have is a one pixel border around maximized windows so popup follows fitt as well... I think that themes should allow the user to add/remove extras that not everyone wants (ie winamp buttons, rainlandiers) without having to change the entire theme to fit it in there... so a more spaced out lay out probably. I've been planning a new theme all day... I thought these were some things that I'd like to see in more themes that would make them a little more friendly to download... oh yeah and if you put a nice html explaining some of the finer details... no one knows everything that your thinking (sometimes I don't know what I'm thinking)... really great features can get hidden and it takes a while to find them if at all.