Can I Have a Custom Redirect after Prosites Checkout?

Team WPMU,

My site is a fairly complex one, and I wanted to redirect new users to a custom Welcome page that explains how everything works, offers a tour, etc, etc.

When someone signs up for a new blog, they are sent to their site's dashboard after checkout via Pro-Sites. I would rather they go to the Welcome page instead. How can I change this?

Thanks!
Rob