Originally Posted by fideba
The main difference is that Core2Duo is a 64bit processor, as where the CoreDuo is 32bit.
It's not really the "main" difference. The biggest difference is that the Core2 Duo* is significantly faster yet is more energy efficient than the Yonah (Core Duo) and Dothan/Banias/etc (Pentium M) processors.
The 64-bit capabilities (intel calls it "EM64T", but it's essentially a copy of AMD64) shouldn't influence your buying decision, since they:
- require a 64-bit OS (Win2k3 Server x64, Vista, Linux, etc)
- show little performance gain, especially for games
- often even run slower in 64-bit mode, since some drivers aren't optimized for 64-bit yet (especially graphics)
EM64T is nice, since it helps future-proof the system and might help later down the road once Vista is released. But 64-bit is little more than a bullet point on a list of marketed features- it's just 64-bit extensions to registers and allows native 64-bit addressing (in short, more ram).
So the real reason to wait for Merom would be for the performance.
*Merom is the codename for Conroe's mobile variant, so I don't know if it'll even be called "Core2 Duo" when it's released.