I would gladly pay 130$ for Snow-Leopard, I didn't shell money for Leopard, useless feature IMO, I got it with a new machine through. Tiger and Leopard were IMO lame update, nothing really more then 3rd party incorporated into the OS (virtual desktop for example). The only real feature was spotlight and meta information search. If you give me a faster OS that can pull out more of those multiple core and GPU with the same hardware, it's a freaking good update. I remember the old day of OS X (I have use it since 10.0 beta), when a major update were equal to more speed on the same hardware. Tiger and Leopard are the only one that slow down on the same hardware and give mostly eye candy.
Make it as rock solide as 10.2 was, solve the wireless network issue many have, the keyboard issue... and make it fast, I will the first in the line to pick this baby up.