I exported it and zipped it up. I believe this should work. I've never exported or imported a theme before. I did very minor tweaking of the colours from the default installation to get things to look like my setup. I don't believe I changed the font. I did do some work on the Window Title, Status Bar, and Notification Area Icon Tooltip. I carried over as much as I could from the older versions of foobar2000.
i have just found a rather nasty bug with foobar - every song i play it changes the mp3 tags, winamp doesn't do this, nor does wmp - going to see if itunes does it