Its very confusing and im still trying to figure everything out so please correct me if im wrong here. Intel announced intel core 2 duo processors, the second version of the intel core brand (the name replaces the pentinum brand) which supports two processors and will be 64bit compatable unlike the original core duo's. There will be intel core 2 duo conroe for desktops and intel core 2 duo memron for laptops, these cpu's will power the 2nd generation of intel-mac products. Woodcrest which replaces xeon's and could possibly be used in future intel powermacs. It has been said that apple is releasing macbook pro's and imac's with this new cpu and will be released sometime after august.
It is also rumored that intel is planning on releasing intel core 2 solo cpu's with one processor instead of two. Also another rumor is that the cpu in todays duo core imac's can be replaceable and upgradable with the new core 2 duo processors since it isnt sodered into the motherboard itself.
Heres the release dates i got off macrumors.com
MacBook with Core Solo/Duo - Very soon
Mac Pro with Dual Core 2 Duo chips - August
MacBook Pro with Core 2 Duo chips - September
iMac with Core 2 Duo chips - October
With this said i cant wait for apple to release their very own 64bit OSX system but we wont know until WWDC.