Linux has lots of free software

Win XP on that machine will get you a slower, less useful machine than one running Linux.  All
the open source software that can be added for free to the unit is a really good selling
point.  Those who will buy the EeePC are not likely to want to run Photoshop or large business
apps on it.  Considering that its a low-cost machine might also mean that they don't have the
hundreds of dollars to spend on software.  

I think some will buy the Windows version and then change it to Linux afterwards, just to be
able to get the cheaper machine.  At least, one can buy the EeePC knowing that its fully
compatible with Linux.

I guess Microsoft is still able to stick in their "tax" on software...