No word yet on whether the default rendering mode will be improved as well, but Microsoft program manager Scott Dickens provides some details about the final IE 8 beta on the IE Blog:

The next public update of IE8 includes improvements to Compatibility View that help end-users when they visit web sites that are not yet ready for IE8’s new, more standards-compliant defaults. This blog post describes the technical background and how this new functionality works.

Despite all the outreach to sites, we saw from the telemetry data that IE8 Beta 2 users still have to use Compatibility View a lot. Looking at our instrumentation, there were high-volume sites like facebook.com, myspace.com, bbc.co.uk, and cnn.com with pages that weren’t working for end-users with IE’s new standards compliant default.  We could also see from our instrumentation that not all IE8 visitors to those sites were clicking the Compatibility View button.  So, large groups of people were having a less than great experience because they weren’t aware of the manual steps required to make certain sites work.

And let’s not forget Gmail and many other Google sites.

When users install Windows 7 Beta or the next IE8 update, they get a choice about opting-in to a list of sites that should be displayed in Compatibility View. Sites are on this list based on feedback from other IE8 customers: specifically, for what high-volume sites did other users click the Compatibility View button? This list updates automatically, and helps users who aren’t web-savvy have a better experience with web sites that aren’t yet IE8-ready.

OK. I guess this makes sense.

And for those who are curious, the dialogs discussed in this blog post are available in the Windows 7 builds I’ve seen, but the option titled “Include updated website lists from Microsoft” is grayed out.