I second what GadgetGuy says about those who aren't really expecting support. They would generally not buy from you.
I always end up buying some high-end laptop that is never really supported by the vendor when it comes to putting linux on it and so I have to hack around to get things working. But basically I do all that I must in order to get it working. I never expected any support from Sharp (I bought Sharp laptops, namely the Actius MM20 and Actius PC-AL27, very nice... both of them) and never got any. They never said they'd support it so it didn't matter.
Depending on whether you've got the time and/or ability to create very useful applications, y ou may be able to get business simply from providing better software or customized solutions. Either way, Sharp Zaurii won't ever really be an "in" thing like an iPod. I personally don't care for the iPod so much but it just works for most people and it looks cool.
Unfortunately the Zaurus looks cool, really cool in fact, but not everything "just works" and usually do anything neat or what people would expect standard these days (bluetooth support) isn't and doesn't work out of the box.
EmperorLinux has made a nice business for themselves by taking laptops that may not normally work very well (or at all) with Linux and created custom kernels and software sets to make them work perfectly (or very nearly). Things that cause people lots of trouble (suspend/resume, hibernation, etc) on laptops under linux are handled by EmperorLinux so end users don't have to bother with it. Many people buy their laptops just for that reason. The end-user may very well be capable with linux systems but just not want to bother with the headaches of getting a laptop running right.
Might want to check them out. I personally have never bought a laptop from EmperorLinux but I have thought about sending in my MM20 for a depot install. I just never got around to it