Jason: Thanks for this very interesting article. I thought you might be interested in some improvements that I've made to this process. Using your SQL as inspiration, I've ran with this idea and created a fairly generic stored procedure that will run data driven subscriptions for delivery to file share as well as email. In addition, this code will handle a variable number of parameters to be customized.
I put my sql and a writeup in a blog post here:
http://spilich.blogspot.com/2007/11/using-data-driven-subscriptions-in.html
feel free to let me know if you find this useful.
Regards,
M Spilich