I guess you didn't do your homework. Dell is selling a new laptop (model: Precision M4400) with Red Hat Enterprise Linux 5.1 64-bit preinstalled. I read an article that HP is coming out with a modified Ubuntu OS laptop soon.
It is not worthwhile to sue a laptop manufacturer in Hong Kong for not offering you an OS option.
Various Linux distro have come a long way. They're getting more and more user friendly. However, Linux is still relatively difficult, geeky and therefore, not as poplular as Windows. Most of the laptop manufacturers think that the Linux market is insignificant to warrant a major effort to produce more Linux based laptops. You have no idea which Linux distro would work 100% with any particular brand or model laptops.
Just take a look at the Ubuntu forum and you will realize that a lot of people had problems after installing Ubuntu and found that the Wireless cards, video cards or the touchpad didn't work. I was lucky that Ubuntu v8.10 (installed on a USB flash drive) works 100% with my old IBM T-40 and Lenovo X60 and 61s. However, I did find a few obvious bugs.
No doubt that Linux will become more and more popular in the near future. The reasons being that 1) the Gnome, KDE graphical interfaces are becoming more user friendly. 2) It is license free. Just take a look at Splashtop, HyperSpace, Ubuntu v8.10 and gOS, people will agree that Microsoft's days are numbered.