I was interested to read that Google is abandoning Gears in favour of HTML 5.
While that makes sense, it is a hassle for developers who have developed for Gears, since there are differences between features such as HTML 5 local storage and Gears LocalServer. The Gears API was tidy and effective so in some ways I’m sorry to see it go, though a broad standard will be much more useful.
Still, this does mean that you can develop to the HTML 5 standard for Offline Web Applications with some hope that, although broad implementation is lacking now, it will come in future. Even IE 9 is likely to have a fair amount of HTML 5 in it.
It is a critical standard because the success of something like Google’s Chrome OS will depend on it. Nobody can count on being always connected.
In the meantime, there are also offline features in Adobe Flash and Microsoft Silverlight.