Google Gears for offline browsing

I'm a couple of days behind in the news here (darn vacation days!)... but Google Gears is out and promises to shake up website development as it uses browser extensions to offload data down to the client instead of making continued requests to the server.  Of course the catch is that you have to download something first.  But there's already Ajax tools for it.

What do you all think about this?  Hype or hope?