Good to hear... I love the deskbar. I even got a few other people interested only they were iTunes users and so couldn't use the playing now features.
My suggestions are to make it work in a similar way to this program:
http://www.obdev.at/products/launchbar/ It is Mac OS X only but is also similar to the search light features apple are incorporating into tiger, the next version of OS X. Basicallly it works in a very similar way to deskbar but takes things a little further. If you are searching for a song, for example, you type in the artist and it then lists all their songs to choose from. If you are looking for a word doc, type in the title and it appears.
It works for everything. Inernet history, application launch it is very powerful. There is nothing like this on the PC so I think you could have something very special on your hands. And lets face it longhorn is not going to introduce search facilities into explorer for at least two years!!
Adam