Blink? Well, it’s a new rendering engine for Chromium with a big mission statement: “To improve the open web through technical innovation and good citizenship”
Why is Chrome spawning a new browser engine?
There are two main reasons:
The main reason is that Chromium uses a different multi-process architecture than other WebKit-based browsers. So, over the years, supporting multiple architectures has led to increasing complexity for both the WebKit and Chromium communities, slowing down the collective pace of innovation.
If you wish to understand better this new story I would recommend you to read Alex Russell excellent post on it: http://infrequently.org/2013/04/probably-wrong/ and for the ones the like (even more) details: The Developer FAQ contain more.