After reading the recent blog post by Amazon about their "cloud enabled" browser called silk, I went into a minor panic. I couldn't find any immediate information about the rendering engine or any technical details about what they actually doing. After some digging I uncovered some job postings that seem to confirm they are using webkit for their rendering and are leveraging SPDYon the network protocol layer.
This is great news for developers as webkit is already well established and most of us won't be immediately impacted by SPDY (well actually, your ajax experience might be impacted, but that's another topic entirely). All told this isn't as big a technological change at the front end and is more of a story about amazon trying to use their infrastructure to make the mobile browsing experience better. Frankly, this is a scaled up and modernized version of what blackberry did years ago (are they still doing that?).
NOTE to Silk team -- please implement an HTML5 native datetime picker on your device that doesn't suck so everyone else will follow. This is a sore point for the mobile webkit experience right now and recurring problem that gets solved in a variety of "not so good" ways.