After more than 5 years (!) of working on the Google Reader team, I'm switching to working on Google Chrome, and specifically the "web platform" piece that uses WebKit.
Reader has heen a lot of fun, I got a lot of things done and got to interact with a lot of users. Though Reader is by no means done, I've been having an "itch" lately to break out of my frontend development niche (where I've been working at higher and higher levels of abstraction lately).
I think there's still a value in knowing how things work at lower levels (even if there's way too much to know), and as much I told myself that I should skim through the Apache, Linux kernel or V8 sources to understand how they work, I never quite had the time. Now that web browsers are approaching OS levels of complexity, it seems like a good time to be forced to dive in.
Of course, the hope is that my web development background will help inform my Chrome/WebKit work, and I'm not the first to make this transition. It'll also be an interesting transition to be working on an open source project, with my (so far not very interesting) commits visible to the world.