A public BETA of Internet Explorer 8 is now available for download at http://www.microsoft.com/ie8. The Internet Explorer team provides a good overview of what you’ll find in BETA 2 at:
Especially note these paragraphs under “Platform” in that post:
IE8 is more interoperable with other web browsers and web standards. The contribution of CSS 2.1 test cases to the W3C is an important in order to really establish a standard way to assess standards support. We think that CSS 2.1 remains the most important place to deliver excellent interoperability between browsers. We think developers will enjoy the improvements to the built-in tools, as well as the other opportunities to integrate their sites in the user’s daily life with Accelerators and Web Slices. You can find more information at the IE Development Center, http://msdn.microsoft.com/ie.
After deciding to default IE8 to the most standards-compliant mode available, we wanted to be sure to address compatibility concerns for organizations and individuals. Would websites that expect IE8 to behave the way IE7 does create a problem for end-users? Since March, we’ve been telling developers about a small change they can make to their sites to tell IE8 to show their sites as IE7 does. Many have – but there are a lot of sites that may have not yet addressed this. The Compatibility View button (new to IE8 Beta 2) is a good solution to provide end-users a good experience as the web transitions.