listen to the '2008 Q3 Earnings Conference Call' where they talk about this. they also reveal some other very amazing details about the insides of google, like how they are protecting their foreign revenues in the wake of the rising US dollar.
This is great. I was actually thinking about moving away from Gmail because I need to manage a separate email for my podcast and the emails from fans, but I didn't want it integrated directly into my inbox.
While the styling still feels a little rough the functionality is great and it's a much needed enhancement for Gmail.
This goes back to what I said, Gmail needed more changes and improvements and they need to drop the Beta for the entirety and only apply it to features inside the Labs.
Not too long ago I thought web apps could never really compete with desktop apps in terms of usabilty. Meanwhile I clearly prefer Gmail over Outlook. Attaching files via drag&drop is the only thing I really miss. Great job, Gmail team!
This seems to be the payoff of focus. Ever since they cut back on the number of fledgling products they're willing to spend time on, the ones that have traction seem to progress faster.