I'm getting the itch to try Windows 8 but I don't want to install it on any of the machines I have. I checked the upgrade advisor and I would lose too much functionality of some things that are key to me. The biggest thing is that I would lose DvD playback on all machines since none of my current solutions are compatible. The XP machine has HP QuickPlay which can play a DVD from a single button push when the machine is off, only loading the necessary parts of Windows and not having to do a complete boot. This feature was removed for Vista because they couldn't make it work in that OS. Some of the HP specific drivers and utilities are also not compatible. Another big issue is my legacy games that I had to do a lot of configuration to get working, especially in Win 7 and there are a couple that will only work on the XP machine.
Therefore I'm left with the option of buying a new machine with Win 8 preloaded and I can't justify that.
You first have to check the HP website if your pc has any Windows 8 driver updates, if not, check the component manufactures website.
Yes, some games are not compatible with Windows 8 especially online games. But they will update it soon.
I had a hard time playing Battlefield Heroes but they released an update for Punkbuster so its ok now.
Or you can save all important files and everything and take some time off and install Windows 8 and check for yourself if its worth it and if not, you can revert back to Windows 7.
You shouldn't buy a new pc now. Wait till Intel's Haswell chips are out by the middle of next year.