Well, here in the states you pretty much have to bite the bullet and pay Microsoft's ransom and get your netbook pre-loaded. Some manufacturers used to install a little application that asked you to agree to Microsoft's EULA before the starting the desktop, which you could then deny and have a chance at getting your license money back, but I've purchased three netbooks from various manufacturers in the last few years and none of them had the app. I just grit my teeth and blow Microsoft away. Anyone who says Microsoft doesn't have a monopoly is blind.
A few years ago I stumbled upon a web site that sold ultra-light laptops that specialized in linux on their machines but were still much more expensive than I could afford, I think they were in the realm of $800-1000 so I never purchased and I've forgotten their url, some kind of letter-number combination, like pc2049.com or something. I wish I still had that url so I could see what they are charging for those machine today.
Here in India I bought two Athlon dual-core laptops in the past three years, both from the Acer Aspire series. Both came with Linpus linux preinstalled, which was really only good for checking the hdd capacity and amount of memory and doing an lspci, so I promptly replaced it with OpenSuSE, of course.
Really good performance for the price (sub-US$500). But maybe you're looking for something more powerful.
I'm not connected to Acer in any way.