Well, not on all of them, but on some of them it seems; namely the new XPS M1710 notebook that we reviewed back in July.   This new model will feature the Core 2 Duo T7600G or T7200 CPUs and 512MB GeForce Go 7950 GTX or 256MB GeForce Go 7900 GS cards from NVIDIA.  And if you get the daddy-mack configuration, Dell is going to give you the keys to overclocking that dual core processor all on your own.
Dell to Allow Overclocking on Core 2 Duo Notebooks - Mobile 5
Powered by Intel®  CoreTM  2 Duo
The next generation of Intel dual-core processors have arrived. The Intel Core 2 Duo offers adrenaline-rush performance, giving up to two times the CPU speed for gaming and entertainment versus the Pentium®  M chip.1
 
Learn More about Intel Core 2 Duo Processor
 Dell to Allow Overclocking on Core 2 Duo Notebooks - Mobile 6
Dell to Allow Overclocking on Core 2 Duo Notebooks - Mobile 7
Genuine Windows®  XP Media Center Edition 2005
Genuine Windows®  XP Media Center Edition 2005 offers enhanced multimedia handling and management versus Genuine Windows®  XP Home Edition, letting you take control of your home and mobile entertainment experience.

The XPS 1710 is Windows® VistaTM  Capable. To learn more, see http://www.dell.com/content/topics/global.aspx/solutions/en/vista_pcs?c=us&cs=&l=en&s=gen.
 
Dell to Allow Overclocking on Core 2 Duo Notebooks - Mobile 8
Raw Power Unleashed
Take the gloves off with the fierce and unrelenting performance of the Intel Core 2 Duo T7600G processor. Putting 2.33GHz of raw power at the heart of your machine, this extreme-performance technology is not only one of the fastest mobile processors available.