I put the Consumer Preview of Windows 8 on my laptop today; my first impression (admittedly after only an hour or so - but that would make it a "first impression") is that it would work nicely on a tablet, but I didn't feel at all comfortable using it on laptop. It's a pretty jarring transition from Windows 7, more so than going from XP to Vista or Windows 7. It's reminiscent of Ubuntu's new UI, more than anything else (at least to me). Seems like stuff was moved around just for the sake of it.
Hardware detection was pretty good; my mouse, video card and wireless card, etc. were picked up, but the sound card was not. This is on a recent model Samsung laptop. After 45 mins or so of poking around, I still have not been able to find the "hardware devices" section to try to look at this. Again, it continues the modern trend of hiding the nuts and bolts of the OS from the user.
The default Metro UI is not exactly pretty - it's quite "plain" - but it's good at displaying the basic tasks up front. It's smooth and slick in it's transitions and effects. However, it took me a little while to figure out that to get out of a program, you sort of drag it off the screen (it's a sort of two-stage process that is not particularly easy with a mouse). At least, I *think* that's how you do it...they did not still appear to be running after I did that.
One cool thing was I found an explanation of how to install Windows 8 as a dual boot, but without repartitioning the system disk drive. Some versions of Windows 7 have the ability to mount and use a VHD (virtual machine) disk image as a disk at boot time ("Native VHD Boot"), so you get better performance than running in a VM from Windows 7. Pretty slick. One thing I noticed, after I went through the "diskpart" step, the Windows 8 installer said it could not use the VHD partition - however, when selected, it worked fine.