i saw some tweets a couple of days ago referencing a release preview blog that was posted and pulled because it posted early. well, i looked off and on for an announcement about it yesterday but ended up missing it because i was out.
long story short, if you missed it too, it's available now. :) now, consider your options before you move forward. there is no going back to what you had before so be prepared. the only going back is reinstalling.
speaking of reinstalling, if you're upgrading from xp, vista, or 7 the good news is there are some things that you can keep. windows 7 is the friendliest in that respect. if you are running one of the earlier windows 8 previews, put on your sad panda face because you will not be keeping anything relative to programs, windows settings, or account info. that detail is available in the faq.
this morning i'm taking the plunge and installing the release preview. that means i'll be spending the weekend reinstalling apps. :) joy. good luck. if you're doing the same thing, let me know if you run into anything worth mentioning.