"It’s a bit like augmented reality, a layer inserted between what leaves the server and what hits your brain." Yes. Also: see Ben's comment about the browser as weapon.

"The current browsers, including Firefox, just can’t cut it. JavaScript isn’t fast enough (thereby limiting the UX), browsers are single threaded and they aren’t stable enough. If Google want to challenge Microsoft (or anyone else for that matter) in the desktop space they needed a better platform... Google’s solution is I think much neater - build an open source browser that supports multithreading, fast JavaScript execution and stuff Google Gears into the back end so it works offline." Now that's a good explanation.