This is an updated repost,  Sure core2duo dualcore laptops are great but be careful you don't pay over the odds for a dual core machine. Although it's old news you've now got corei5 and corei7 machines these days at pretty comparable prices. Obviously dualcore machines have 2 processing cores on one processor chip which is like having 2 processors in one. The number of processing threads that processor is capable of determines its simultanious processing ability.
- corei5 processors are basically quadcore processors capable of 4 processing threads (that's 4 processing cores on 1 processor chip although some come with 2 which I can only assume are capable of fewer processing threads)

- corei7 processors - most are basically quadcore processors capable of 8 processing threads. (thats 4 processing cores but due to the architecture its capable of 8 simultanious processing threads thus will show up under task manager with 8 CPU readouts. but...

... there are some corei7's that have 6 physical cores and are capable of 12 simultanious processing threads thus appearing to have 12 processing cores under task manager.

That's right, with corei7's it apparently does 2 processing thread per core. Despite the fact that Taskmanager is telling you a machine has 8 processor cores (or 12 depending on which one you have) when using a single i7 it apparently does in fact only have 4 actual physical processing cores (or 6 again depending on which you have). The anology of multiple chefs reading from the same cook and not necessarily from the same documented page was used. But even then that anology would still suggest to me that some sort of additional seperate processing was still going on despite sharing the same source of instructions from cache memory but what ever I guess. Some people have used the term vitural processing cores, but why would it have virtual cores on the CPU since the CPU is a peice of hardware. As far as I was aware virtual means none physical software based solution and aren't as fast as hardware based solutions especially for something like the CPU, but again whatever I guess, I didn't design the thing so they could basically tell us whatever they wanted from a vast array of plausible explanations and we'd just have to beleive it.

Whatever the case you can be sure it'll be a reason to extend the anticipation and the money making potential up until the point they do decide to officially let you have a physical 8 or 12 core processor in your laptop. Not to mention the fact that on board GPU technology on the main CPU had been knocking about in a deployed capacity for some time before they actually decided to let general consumer know about it as if it was something new. Ungimped CPU's for an additional $50 anyone?
Anyhow back to what was contained in the original post:

...despite having more processing cores and processing threads the mobile versions are more efficient and do in fact use less electrical power then their dual core predecessors. In some cases roughly the same at the higher speed clock cycle ratings.