Amazon's Kindler Fire maybe not like what you want. It runs Android, but a full customised Android that you don't have Google Market, Gmail, and the Android update ... It officially only supports Amazon's services.
In other word, it's a branch out from Android master. And it will never merge back.
They were a bit cagey when pressed for how often it would be kept up to date with new OS releases. The best they would say is "We're a tech company. We'd like to think we'd be better at providing OS updates than the Telcos". Reassuring? Perhaps not.
Amazon definitely plan for this to be an Amazon device, not a Google device with Google add ons. I think its a very smart move on Amazon's part. I reckon that competition is a good thing.