Just confirmed with Apple's Tech Support that Logic 9 is NOT fully 64-bit compatible even with Snow Leopard Installed - still based on old Logic 8 platform. This confirms what I've been reading on other forums all along and my personal test have confirmed this to be the case. There is no date as to when Logic 9 will have a release allowing 3rd party plug-ins to utilize all memory available (non-Vienna types).
I will add that Logic 9 combined with Snow Leopard is handling the core processing much better. One of my sequences was chocking on a single core prior to loading Snow Leopard. That issue has appeared to have gone away. The 8 cores are now balanced thanks to Snow Leopard.
Neither Cubase 5 nor Pro Tools are full 64-bit and still waiting to release theirs as well. Will be interesting to see who get's their's to market first.......
Thought I'd post this just in case anyone was wondering.......