Yes, there are plenty of us who read on PDAs and smartphones, and are constantly seeking some love in this market of dedicated devices. I was able to bring most of my reading apps over to my WinMo smartphone from my PDA... but I'd love to see a Kindle and Barnes & Noble app as well, and just feel I'm being neglected by all parties. I'm actually buying fewer books, as I cannot read DRM'd books from Amazon or B&N on my smartphone... and no one seems to care.
But even we're not alone: People who own dedicated devices often find themselves shut out of other bookstores with competing formats (or DRM). It's an industry-wide problem.
The best thing for you to do is not only to tell those booksellers what you want... but tell them you are spending your money at other bookstores that do not lock their content with DRM or use proprietary formats... money that could be theirs. There's some good indie stuff out there... you just have to look harder for it.