There are very few true PC gamers that'll willingly buy a laptop over a desktop, primarily because the performance-price difference is so great. Rock's just added an Intel Q9000 chip to its flagship gaming laptop - the Xtreme 780, but I suspect the majority of gamers out there simply won't care.
It's not even that great a machine. Quad-core aside, the 512MB Nvidia GeForce 9800M GTS is merely adequate, the 2GB of memory will look very meagre before the end of 2009, and a 250GB hard drive is considerably less than most gamers will need. For £1700, which is what the Xtreme 780 costs, you could make two desktop PCs that outspec this laptop.