FWIW, metro apps are not fully featured but rather feature crippled. Take Chrome's metro version for example. It is just the forced-fullscreen version of the desktop one. You can still open insane amount of tabs.
But there is already one integrated into Windows 8, there is also sharing and searching integrated
Sharing
http://i.minus.com/ixWDWz6QqMRvG.jpg
Searching
http://i.minus.com/ieIlX6e9QyL16.jpg
shifting search to a different app/service with a click
http://i.minus.com/i8CxZ5i2wILEW.jpg
I'm not trying to become the Windows 8 advocate here but just showing how it has utility and value in many uses for me.
This isn't a technical issue per se, since it would be possible to produce these apps for the desktop.
Out of curiosity, is there anything the hot corners can do that you can't do using the Windows key launcher?
* Start Screen(lower left or Windows key)
* Recent/Running Metro apps(upper left or Win & Tab) http://i.minus.com/iD8rJOYWLWoHU.jpg
* Charms bar (upper or lower right or Win & C) http://i.minus.com/iKqyzIcITSAfB.jpg
I am about as a hardcore Desktop user as it gets, I have a custom build pc with 3 screens, custom mouse & keyboard shortcuts, steam, Photoshop & Dreamweaver user, etc...
I've been using Windows 8 since the Developer previews, and while some things have taken a while to get used to(like the hot corners), I'd have to say overall Windows 8 is a step up from Windows 7 in every way, I would hate to go back to 7. The Start Screen makes the Start Menu seem archaic.
Some pics of my setup:
http://i.minus.com/iqRDyV3Cdz4M3.jpg
http://i.minus.com/iUyzL0SkQgSD5.jpg
http://i.minus.com/ibsaj7IkT3usDj.jpg
http://i.minus.com/i2xfTeTriMwQ8.jpg