I sent Amazon an email and I got a response saying that my comments have been forwarded to the Kindle team. I've spent a lot of money with Amazon over the years, but until they change their current policy, I won't be spending any more with them. I'm even disinclined to buy anything from Mobipocket, or even mobi files, given the fact that money goes back to Amazon.
I've also sent emails to a number of publishers, but haven't had any response yet.
I've appealed to publishers of ebooks on the Mobipocket forum to not lock themselves into Kindle format:
http://www.mobipocket.com/forum/viewtopic.php?t=9152
I think the real problem is, though, is that any outcry is from a relatively small community. Most Kindle buyers will probably think that the Kindle is a first of breed e-book reader, and will happily buy content from Amazon without realising that Amazon is attempting to kneecap competion. It may also be the case that publishers will think that publishing on non-Kindle formats isn't worth the effort.
-Wayne