Personaly, I'm stuck with an old buget price P4 PC which tends to get a bit glitchy and unreliable
with my Line 6 USB Tone Port UX2
Wish I could afford something new, but always interested in keepinp up to speed on current technology.

To save folks time wading through the "Sound on Sound Forum" thread;
this link posted on the 6 Dec is an interesting read about the 'state of play' in recent 'off the peg' laptops and usb audio interfaces/drivers.

"Choosing a Laptop for Music Making: Part 2
By Robin Vincent on 11/30/2010"

http://en.audiofanzine.com/pc-laptop/editorial/reviews/lifting-the-lid-on-audio-laptops-the-test.html