I will give you a guarantee that when I have figured out how to compile for the N900 and have actually managed to learn another coding language reasonably well, I will try to do this if no one else has by then.

However, do keep in mind that I am just starting out, have very little time daily to learn a programing language, and that when I DO learn enough to be of any serious help to programing anything, I have a couple of other things I view as higher priority.

In the meantime, I would look at the wifi signal applet source code, and find out if there's some dbus call or other API to fetch what desktop you're on. Then it should be pretty easy to just take the code for the wifi signal applet, clean out the wifi parts, and put in the desktop numbers instead. Then either compile in madde or scratchbox, or figure out the mystery that is the autobuilder.