The Windows 8 interface has had the Start menu redesigned and rethought. It seems better suited for use with a touch interface than a traditional keyboard and mouse. Myself, I don't use any touch interface devices, and I find it cumbersome for desktop use. I also find that the Search function is no where near as intuitive as that included with Windows 7.
The use of the Start page with a mouse is inaccurate and difficult to control. It's not like you can swipe with the mouse to scoot the page from side to side, but instead you must move the mouse all the way to the edge of the screen and wait for Windows to move the page for you, or grab the slider at the bottom of the screen. It is a bit uncoordinated that way, and not so useful for a desktop.
Having a large graphic to start your programs and the ability to arrange them in a thoughtful manner are a plus, especially from across the room, as in an HTPC setting, however the use of shortcuts and the largest icons in a Windows Explorer folder are just as effective in Windows 7, though it is not as pretty.
The Desktop feature operates nearly identically to that of Windows 7, though I still go to the bottom left for the Start menu, even after 2 months of continuous use.
Also, the Apps selling is annoying. Delete, delete, delete, and use your own established programs from within the desktop if you don't want to continuously spend new dollars on minimally functional apps. I know that's a personal opinion, but it's mine, so I share it.
It has been a bit glitchy, restarting due to unexpected failures, and a bit halty at times. I cannot say at this time whether that is hardware, driver, or OS related, as the hardware is all new and has not been tested with another OS.
Oh yeah! I almost forgot! Turning the thing off is unnecessarily complicated by having to go to the settings window to do so, or to log out, wait for the "Leaf" (initial) screen, then click to get back to the log in screen, just to find the power options. That one wasn't very well "Re-thought"!
In all, I don't find it desktop friendly, but if you are more accustomed to a touch interface, it may be of use to you over Windows 7.
I'm using "Windows 8 Release Preview" on an AMD E350 APU with 8gb ram and a 60gb SSD.