said by Blackbird:One should always be careful about electing to upgrade to a major, new (in terms of functionality or UI) OS on a system that is several years old or more. Over the years, I've found the most consistently surest, safest path is to migrate to a new OS when moving to a completely brand-new system. Certainly those who are skilled in wringing out bugs or are expert with the ins and outs of a new OS and its installation/tweaking can upgrade an OS successfully - but it's all too often not to be entered into lightly by folks with lesser skills. The older your system hardware, protocols, and drivers, the more likely you'll come to regret a major OS upgrade decision...
One nice thing about the release preview is that it allowed people to test and play with things and see how it works out before actually having to commit to buying it. I used both pre-releases myself and so had a pretty good idea that everything would work out fine if indeed I decided to buy 8 when it was released. The preview is a very nice thing to have....