Microsoft has posted a second IE9 Platform Preview for developers to fiddle with. The IE9 Platform Preview 2 was completed last week and is now available for download.
You should only download it, though, if you know what you're doing, for, as a Microsofty explains, it's not for n00bs.
“These Platform Previews for Internet Explorer 9 are designed specifically for web designers in mind and focused primarily around same markup and what that means for developers. These Platform Previews for Internet Explorer 9 are not betas. There is intentionally no UI – not even a back button or an address bar – and they’re designed to be able to run side by side with your regular browser,” explained Brandon LeBlanc, a Windows spinner.
If that doesn't put you off, click here. Microsoft says it welcomes feedback.