Thanks for this thread.

I got a working Leo + Snow Leo working.

After I installed Netkas' EFI 10.3, it seems that it is loading the extensions from /Extra/Extensions ONLY from the booted partition, making it easier to dual boot.

That is, on the Leopard partition I have a /Extra/Extensions with Leopard's extensions. On the Snow Leopard partition, there is a different /Extra/Extensions with Snow Leopard's extensions.

If someone is having trouble with Chameleon 2 RC3, try using EFI 10.3 "/boot" file.