@Neil Barnes: adverts
"The Amazon connection doesn't strike me as The Way Things Should Be[tm] and seeing adverts for paid software in the software centre was something of a surprise, too..."
While I don't like the intrusive Amazon search, I have no problems with the Software Centre listing or advertising paid-for software (and other things such as magazines). It's both heartening to see how many vendors consider it's worth porting/building for the platform, and if it earns Canonical commission then why not? Someone has to pay for the software development and I'm sure Mark Shuttleworth's is not infinitely wealthy. I see it as a welcome step towards the mainstream.