Proof

Here's proof that you CAN get Leopard running on a non-supported machine. I think the easiest way to do it is open the computer in open firmware, type in a few lines of code that make it think there's a bigger processor inside and bam, you've got Leopard. Here's the link to the procedure I used from Lowendmac.com
http://lowendmac.com/osx/leopard/openfirmware.html