Silk may be a good idea today, but we would like it to be implemented by our Internet providers, not by Amazon. Why should I trust Amazon on what they're doing with my bank account credentials? This is frightening. At least it should be possible to specify which web sites may or may not use this Amazon's proxy via black/white lists. But unless silk is open source, how to be sure this will work as expected ? The worst is that I'm sure there are people out there who are going to buy this Kindle Fire, just because it has Silk..
Have a look at this post which summarizes our feeling:
Amazon's Fire isn't that interesting – but Silk is
(I've read that Opera does something similar, but this capability hasn't made the browser a household word. Of course, the good folks behind Opera lack Amazon's cloud servers. And its marketing department. So there you are.)