Amazon has done an amazing job with the Kindle.
But, I have to agree with the posts about ISBN rules, at least to this extent. The ISBN system, whatever its flaws, is the international system for identifying books. The ISBN agencies have decided that each version of a book should have a different number.
It makes sense for Amazon to adopt the conventions, in my opinion, although Amazon may have sufficient market influence to compel a rethinking of the eBook/print copy numbering rules.
Bowker offers ISBN in groups of 10 for $275.00 and bar codes at $25.00 each. A print book could obtain a different ISBN for a Kindle electronic edition and that would be that, no? Amazon could charge a flat fee of $52.50 for providing the number and the place in DTP that would accommodate the little bugger. Or, if you are self-publishing, as publisher you could acquire the number and bar code yourself and just type it into the space currently provided. Personally, I'll use my print edition ISBN with the confidence that Amazon will find a way to link the Kindle to the print edition. Then the buyer will have a choice. Simple, huh?