Comment on Hyperspaces

I like the idea of having separate wallpapers for each space, and this app does it quite well. However... I've been looking all over for an app / script that enables me to move the currently active window to any given space. Lets say I want to move Firefox from Space1 to Space4. This could be accomplished by pressing Ctrl-Cmd-4, for instance.

This is a common feature in all the VDM's I've tried on Linux (even one I tried for Windows 7). I was kinda hoping to see this feature in an app built on top of Spaces.

Why hasn't this functionality been implemented? It would be sooo useful!