If your method is like Halo's then you're porbably wasting a lot of texture space on your shadows. Halo's method seems to create one texture per receiver. How will you shadow objects in a level like that?
I dont follow. Theres not much other way to render said shadows unless each reciever has a texture. Unless your refering to vertex coloring of some sort. If you don't have anything but productive to add to help the masses here, then I suggest you just stay in your corner ditching out copies of your shadow system.
[edit] Halo, your system seems to completely ignore that this will have to cast onto surfaces other then a ground plane. Am I missing something? If so, I will gladly look at integrating your method into the shadow systema s well.