The Chrome store could be more than a link directory, and if that happens it'll be for the same reason Apple's App Store took off: centralized payment. A sane payment system for web apps could be revolutionary, but before that happens we'll need to change the Web's culture. Right now people simply don't pay for web content.
The ability for the Chrome store to deliver local apps, which I suspect you were referring to, is mostly unused and irrelevant. HTML5's offline features can duplicate that functionality on any browser that supports them.
Packaged apps is just one of the many (and growing) features of being a Chrome apps. But packaged apps don't have anything to do with offline storage. There could be a packaged app spec in HTML in the future, but there isn't today. Nor is there a spec for background pages, cross-domain XHR.
The ability for the Chrome store to deliver local apps, which I suspect you were referring to, is mostly unused and irrelevant. HTML5's offline features can duplicate that functionality on any browser that supports them.