If it works in Windows 7, it works in Windows 8. At least I have not found an application that didn't work in 8 yet.
The Start/Metro style/App screen is for lightweight apps.
The desktop is for everything else that everyone is very familiar with.
I have been using Windows 8 every day since the first release and I just upgraded my home Windows 7 computer to Windows 8 Pro with out a hitch.
All of my settings stayed the same. The only thing I had to do was get a new driver for my Bluetooth hardware. It was a breeze.
No, I am not using a touch screen. You don't have to. The mouse works just as well.
Click in the lower left corner of the screen where the start button used to be and you get the start screen.
The mouse wheel acts as the swipe gesture quite nicely.
Both of my Win 8 computers are operating significantly faster. The desktop is ready in 20 seconds from cold boot. I am very impressed with Windows 8.
Is it ready for business use? That depends. Are you willing to spend 15 minutes showing someone how to navigate? Then yes, it is ready for business.