Windows 8 already has hundreds of thousands of "apps"
And before you go there, no, I'm not talking about legacy software.
I'm talking about the ability to launch an app or a website from the start screen. Did anyone in the history of Windows ever complain that there wasn't a Facebook app? I seriously doubt it. They just opened their browser and typed in Facebook.com. Well guess what, now all you have to do is go to facebook.com once, right click, and hit "pin to start". Now you have a nice looking Facebook tile on your start screen that looks just like an app. Is it a Facebook app? Technically, no. Can I launch Facebook directly from the start screen just like any app? Yes. Does it run in full screen? You betcha. Does it have more functionality than any official Facebook app on any platform? Absolutely. If it looks like an app and acts like an app...
Oh man I really wish the Twitter app was already out - Twitter.com. Pin to start. Boom. Twitter "app."
Want a Verge app? Go to www.theverge.com. Pin to start. Boom. The Verge "app" right on your start screen.
In all seriousness though, this functionality is wildly underrated.