WAI-ARIA support in IE8 RC no longer non-standard
One of the good things about Internet Explorer 8, apart from its improved support for CSS 2.1, is the addition of support for WAI-ARIA. If you’re not familiar with WAI-ARIA, you’ll find links to many things related to ARIA in my post Reading up on WAI-ARIA.
Luckily, Microsoft listened to the community and have changed the WAI-ARIA implementation in the Release Candidate of IE8 to use the standardised syntax that other WAI-ARIA supporting browsers use. Read Improved ARIA Support in the IE8 RC for the reasoning behind not using the standardised syntax in the first beta and now changing it.