I've got it loaded on one of my test systems currently. Really, there are a lot of things I don't like. Yes, it's just a developer's preview right now but there are a LOT of things functionally that Microsoft has to fix or it's going to be terrible.
First, the start menu is no more. When you click on Start it loads up the new Metro UI which is specifically designed for touch input only. This means you can't just go to Start -> All Programs to get to your applications anymore, or go to Start -> Control Panel to open that. Pretty much, everything accessed previously by the Start menu takes at least three more steps to access now. Even to shut down the computer you have to hover on the Start menu corner, select Settings, and THEN hit the power button on the left side and select if you want to shut down or restart. Completely pointless.
Next, Windows 8 incorporates the new Metro UI. While this may be a great feature for mobile devices like tablets, its a completely useless function on a desktop computer. So why they force you to have to use it is beyond me. There are several apps accessible from the Start screen (the Metro UI) but I found it completely laughable that NONE of the apps or screens accessed from the Metro UI can actually be closed! That's right! None of them have a close button, an exit option, anything! Once you open the program, it remains running even when you switch to something else which is a terrible waste of system resources and going to cause a TON of problems. I found the only way to close any of those programs is to open task manager and kill the process.
Speaking of task manager, they have a new one! While I kind of like the new task manager, I don't like that it has to be more complicated. There's now a "simple" view which only lists running programs, and then a more complex view which shows the system resources in use, the users, processes, etc. similar to the original task manager in XP and 7. HOWEVER, I found that if you run the original process name for task manager (open RUN command and type taskmgr.exe) you actually bring up the OLD task manager. The new task manager is just simply tm.exe
Another pointless frustration I have been trying to figure out is again related to the start menu. When you install a new program (like I installed Firefox on the computer) it will often times create a tile shortcut automatically in the Metro UI Start screen for that program. But what if you want to pin other shortcuts or programs to the menu? I at first just thought, "Hey, I'll just right click and select Pin to Start Menu." Unfortunately, that does nothing. It doesn't create a tile for it and, as I mentioned before, there's no more start menu either so it simply does truly nothing.
Now, there are some things I do like about it. First, the boot up system has been modified in a sort of hybrid hibernation. From what I understand, the computer stores an image of the system at startup directly onto the hard drive. This way, even when power is completely off, when your computer turns on it will post and then simply load up that image. I was truly impressed with the speed of load up on this system even using a pretty standard desktop with standard mechanical hard drive. It was up and ready in literally two seconds! I can't imagine that an SSD will even be able to help speed up that kind of boot up time by anything! I'm also curious about the new way that they are handling Live accounts. Basically, when creating a user account you can select to use a Windows LIVE account (such as your hotmail account or whatever) to create a user account that then has its settings synced to anywhere you go. If you have Windows 8 with your Windows LIVE account at home, and then drive to your office and log in there with your Windows LIVE account, it automatically has all the same settings as your home computer. Now, obviously there would still be some differences of course depending upon what software you have installed on the computer, but it presents an interesting idea of having very fluid transition from computer to computer and keeping things familiar.
Another feature I really like is including Hyper-V. Now, pretty much no one out there will use this feature directly within Windows 8 unless they are intentionally setting up a server system but I still think it's wonderful to see such a powerful feature of Windows Server 2008 be brought to the consumer level for usage. I was able to install Hyper-V using the Add and Remove Programs and Windows Features menu and had installed a virtual machine also running Windows 8 literally within fifteen minutes. Windows 8 also recognized all my drivers without any problem, including my USB wireless adapter which Windows 7 does not recognize automatically.
All in all, this may be a great advancement to expand Microsoft's ability to work with new mobile devices like tablets, but the functionality that they are sacrificing on the desktop front is truly horrendous. After all, the number of devices that utilize touch input as their primary form of interaction is a tiny fraction of computer devices. It's like Microsoft is willing to cut off its entire market base of business desktop computing just for the opportunity to gain some new customers that play with a tablet.