I'm not normally one to pay attention to a new Windows version until I'm given a computer running it, or I have a support call associated with it. However after the announcement of the retirement announcement of SolidWorks on XP I got interested in what was coming.
I read a brief article listing some of the upcoming features in Windows 8 and was excited to read that "All Windows 7 applications will run natively on Windows 8." There may be fine print, that I didn't get to, but if I can take the article for its word you shouldn't have to worry about waiting for Service Packs or new releases of SolidWorks once you end up with a PC running Windows 8. This article on Engadget lists off a few more, like monitor specific task bars for multiple monitor users.
It looks like the release date won't be till Fall of 2012 so you've got time. But in the meantime, I'll leave you with an image of the revised Blue Screen of Death for Windows 8. Its nice to see they have acknowledged that the old codes were useless. :)