It appears Microsoft is releasing Internet Explorer 8 today at 12pm EDT/9am PDT. I guess I'll have some testing to do today, as I was still experiencing weird issues with the last IE8 candidate I had installed for beta testing.
I'm not sure where they will be posting the full edition at. Currently you can download the last beta (RC1) from their Internet Explorer beta page. I would imagine the full release will show up at http://www.microsoft.com/windows/internet-explorer/, but that's pure speculation on my part.
UPDATE:Looks like the official site for downloading IE8 is http://www.microsoft.com/ie8. Read more at Microsoft Announces Availability of Internet Explorer 8.