According to CNet versions of the Asus Eee PC pre-installed with Windows have already been released in Japan. The US market may come next.
Called the Eee PC 4G-X, it will come pre-loaded with Windows XP Home Edition. It has the same specs as the original 4G model with Linux introduced last fall: 4GB of storage, Intel Celeron processor, 512MB of RAM, 802.11 b/g Wi-Fi, and more.
According to Asus, Eee releases pre-installed with XP may be expected this February or March. Of course, you can install Windows XP yourself, as the DVD with the Eee PC sales packages includes Windows drivers. The manual also has instructions and tips on how to minimize space usage. XP, after all, is a space hog and memory hog compared to the built-in Xandros and most other Linux flavors.
Thing is, the bundled RAM is just 512MB. I doubt if Windows XP will perform well given the limited memory. Best to boost it up to at least 1GB, which is dirt cheap these days.