I don't quite understand all the negative response concerning 8. I received a free copy from MS Tech somewhere around 8 months back and I've been dual booting (installed on an SSD) ever since. For those that are not comfortable with the Metro start screen, there is a fix to return it to the classic start orb.
Windows 8 is very fast, IMO faster than 7 and decimates Vista in terms of speed and memory bandwidth.
8 has removed a few of the features included with previous MS versions, (WMC, for one) but that has been progressive over the last few versions and from customer feedback, many people opted to use open source or freeware apps in place of the bundled Windows apps.
I might add that I haven't had a single issue with 8 other than a corrupt driver for my 3870 X 2 GPU which resulted in an error, but to my surprise the BSOD has been removed from the OS
If you already possess a PC with 7 as the residing OS, I don't personally feel an urgent need to upgrade to 8 since there is little to be gained from the upgrade, but if you're shopping for a new PC don't be discouraged by 8, it's stable and works well.
Finally, the concept of 8 and the metro start screen was to interact with ALL Windows devices; Windows phone and the upcoming tablet also incorporate the Metro screen. Windows 8 makes for a perfect touch screen OS, but as I stated previously if you don't possess a touch screen you may want to revert back to the classic start orb style start screen.