It's a question of context and expectations. I expect people to look at me funny when I walk around in boxer shorts in public, but not at home. Were someone to stand at my window while I'm on my couch and complain about my choice in clothing, I'd have a right to complain.
Your angst over this new system depends largely on whether you consider behavior outside of your browser to take place in a public or private space.
I'd guess that the only way to really dislodge the Amazon widget would be to make sure it remains unprofitable. If it remains a major talking point and doesn't pull in enough money to compensate for its negative effect on community evangelism, it won't last long.
I have mixed feelings about the new system. On the one hand, I respect a lot of what Canonical is doing with linux regarding mainstreaming, streamlining, and even Unity. I also recognize that they are a company and need to make money, and think Amazon integration is preferable to dozens of preinstalled, hard-to-remove junkware applications.
On the other hand, I really don't like the intrusive-by-default nature of the integration, and the fact that I'll have to go tell all the folks I've installed Ubuntu for that they need to essentially disable spyware the next time they do a distribution upgrade.
On the third hand (what, you don't have one?) I'm not sure what other profitable solutions Canonical might implement in a community that values privacy and freedom.
JQuery still seems to be king at the moment. There's some pushback against it in this new world of a mobile web since it adds size to low-bandwidth pages, but there doesn't seem to be a risk that it'll be dethroned any time soon.
If I were looking to make a portable and semi-futureproof toolkit right now, I'd use jQuery as a base, but limit myself to some big features, like dom queries, events, and ajax. Then I'd make sure I had it sandboxed inside all my code via anonymous functions (function($) { /* my code */ })(jQuery); so I could swap in a lighter replacement later on without a headache.
I completely agree, but not everyone will, and that perception is key to the discussion.