This would be amazing.

However, Compiz Fusion is a "compositing" Window Manager not an "app". Thus it would need to replace the Hildon+Matchbox Window Manager. Furthermore while older versions were using XGL based off of OpenGL now it used AIGLX of which I have not heard of support with PowerVR. What PowerVR means to this is 1.) Need open sourced drivers (or very very clever hacking which would be very inefficient) 2.) Modification of Compiz's AIGLX support to utilize Open GL ES 2.0

I'm sure I'm forgetting to mention something. But the point is this wouldn't be a simple port to ARM thing. This would likely require an over-haul to get working. Of course it would be worth it.

If someone gets this usable, they deserve a free N900 for the effort.