anyone can speculate. i speculate that the next macbook will have 2 built-in optical drives, one of which is blu-ray. (sorry, just poking fun at the speculators, who seem to have nothing better to do with their time than to create new threads with meaningless speculation)
How it will run? via computer code
but if you're meaning to ask
How well it will run? go to snow leopard's page at apple.com and see how many technologies they mention apply to you.
64 bit? check.
Grand Central? check.
OpenCL? maybe not a check. Nvidias graphics are supposed to have the best/earliest compatibility, but OpenCL is an open platform, so anyone (Nvidia, ATI, Intel) can program for it, but Nvidia has a headstart
Quicktime X? read the asterick where they tell you the specs of the iMac they tested on.
see? a little legwork on your own could've gone a long way
and none of this was meaningless speculation, it is based on "published" facts.