Android

I understand your concern and agree that a fragmented platform is not desirable, however, that being said some fragmentation has to be expected in a new and maturing OS platform.

Two points I would like to make.
One is the consumer has to be responsible for doing their research into the phone they purchase. If they want the latest OS version they must expect to pay more as it will be installed on a premium phone such as the N1.
Two is when the manufacturers build a branded phoned for a carrier it is the carriers responsibility to provide updates for the phone and they seem to have very little interest in doing that.
My way of thinking when it comes to buying a new phone is buy the latest version of the OS in a phone that meets all your hardware needs and buy it unlocked if possible.