Of course you will need a new kernel as LION uses Darwin 11.0 whereas Snow Leopard uses up to 10.8. Im too AMD user, but can advise you to think forward to switch to INTEL in mid 2012 like me when DDR4 will be commercialised. As what I heard, future APPLE major apps will require SSSE 3 CPU instructions like; FINAL CUT PRO which only INTEL cpu's have. For now you can still run Snow 10.6.8. The only two persons who I know on the OS X scene, who can make a kernel for LION are AnV and Nawcom. So keep in touch!!!