The IE blog whittles down the IE 8 Beta 2 date a bit further:
In addition to the features for developers we showed in IE8 Beta 1, we’ve been working on great new features for consumers and IT professionals (as well as doing even more cool stuff for developers). I’m happy to announce that we’re on track to deliver IE8 Beta 2 this August when you’ll get a chance to see what we’ve been up to in these areas. Furthermore, in order to help us get even more feedback for this global product, we’ll be releasing Beta 2 in over twenty languages within a month of the initial release. This is a big step up from the three languages we released for beta 1 and much more than we ever did during IE7.
On behalf of the team, I’d like to thank you all for your help with beta 1. Since we released Beta 1 in March we’ve had over two million downloads so far with lots of good, useful feedback. We’ve been listening to that feedback and making improvements to our work on an interoperable platform that has full CSS 2.1 support, faster script performance, and significantly more capable developer tools as well as our cool new features like Activities and Web Slices. We’ve learned a lot from this first beta – keep the comments coming please!
Between now and August, there are a few ways you can prepare your sites for Beta 2. First, take advantage of Activities and Web Slices on your site. Second, make sure your site looks great in IE8; as you may recall, IE8 will use our new, more standards-compliant layout and rendering engine for strict doctype pages by default. This may cause IE8 to layout pages differently than IE7 did. If you haven’t had a chance to test your pages yet or don’t want to make changes yet, remember that you can have your site tell IE to use our IE7 layout engine for your strict doctype pages by adding the X-UA-Compatible http header to your HTTP headers or on a per document basis. You can learn more about how to ensure site compat with IE8 on our new IE Compat pages.