So IE8 has now been released, meaning that it will very shortly be in the hands of users for just browsing the Web or for accessing the thousands of Line-of-Business applications delivered through a browser. If your Web site isn't compatible with IE8 then this might not cause a great deal of harm, if it's just your blog or your family photos, but if it is a Line-of-Business application that users rely on to carry out their day-to-day work, then this could cause serious problems if you own or manage this application.
Therefore, why not check that you are compatible with IE8 today, before your users tell you that you're not.
You can download IE8 from here.
I've collected a few links to some of the best blog posts I can find on IE8 compatibility, ranging from ‘these are the differences between IE7 and IE8’, through to, ‘HELP! My site is broken and I need to fix it now!’
http://blogs.msdn.com/ie/archive/2009/03/12/site-compatibility-and-ie8.aspx
http://blogs.msdn.com/ie/archive/2008/06/10/introducing-ie-emulateie7.aspx
http://msdn.microsoft.com/en-gb/library/cc817570.aspx
This is the home page for IE compatibility http://msdn.microsoft.com/en-gb/ie/cc405106.aspx which has additional content.
If you are still having problems, remember, you can raise a support call against IE8 through the Metro Program.