"The Inquirer has an article about how Montreal, CA based Linuxant has created a 'compatibility wrapper' allowing standard Windows NDIS 5.0 drivers to work on linux. After pointing to another project allowing windows printer drivers to work on OS/2 the author asks 'Are printer and network card drivers going to become, over time, a commodity with Win32 drivers one day the 'de-facto standard' run via wrappers?"
Device support and games are about all M$ has on Linux. (And maybe ease of install, depending on which distro you're running.) Once that stuff goes away, we'll see Windows start to get seriously attacked on the desktop. So if I was Bill Gates, I'd be a bit nervous about this...
Watch for M$ to introduce deliberate incompatabilities, viz the AARD code, to (try and) trip up device driver compatability.