Alienware laptops are great as desktop replacements. Fast, leading edge video, etc. Battery life and temperature are not their strong points. They're manufactured by Clevo. You can buy the same systems through Clevo's other resellers (i.e. Sager) for quite a bit less. The <a href="http://www.discountlaptops.com/index.php?section=specs&model_id=1047&category_id=2&category_theme=c1">Sager 9860</a>/Alienware 7700 rock if you have $2.5-3K to spend. You won't find anything with comparable performance from Sony/Dell/et al.
I have my eye on a notch or two down to replace my old junk. One of their <a href="http://www.discountlaptops.com/index.php?section=specs&model_id=989&category_id=2&category_theme=c1">AMD 64 system</a> for $1.5-2K. Shop around.