An article on IEEE spectrum talks about Blake Ross and Joe Hewitt's project called Parakey.
Details are very sketchy at the moment but it sounds like Parakey is aiming to address some problems very close to my heart. It sounds like Free Software designed to replace (or supplement) your operating system with a unified interface where your desktop meets the web. Importantly it appears to offer a solution to the “offline problem” and other important Post-PC concepts. The interesting bits are on page 3. I look forward to hearing more about this project.