The new Alienware has a Core i7 Mobile CPU. Hothardware takes a look at the most powerful CPU Intel has to offer also now found inside notebooks.
Quote from the review: "For quite some time now, Intel has been the undisputed leader when it comes to laptop CPU performance. This advantage comes from the fact that Intel has successfully scaled its desktop processor technology for use mobile platform. That trend continues with the latest mobile processor platform being unleashed today from Intel: the "Clarksfield"-based Core i7 Mobile processor family and the new PM55 Express Chipset.

This marks the first time that the "Nehalem" Core i7 microarchitecture has been ported over to the mobile side. The fact that the mobile version of Nehalem makes its debut only two weeks following the launch of Intel's Core i5 ("Lynnfield") mainstream desktop CPU and P55 Express chipset is no coincidence. As it turns out, the Core i7 Mobile processor die is identical to the desktop version, but uses mobile packaging--as far as the microarchitecture is concerned, Clarksfield and Lynnfield are essentially the same thing. The lower power demands of Lynnfield (as opposed to the original Nehalem architecture) are in large part what enable it to also be used in notebooks..."
Read the full Intel Core i7 Mobile Processor (Clarksfield) Review on HotHardware.