mattur - 2:01 am on Jan 24, 2011 (gmt 0) [edited by: mattur at 2:10 am (utc) on Jan 24, 2011]
Browsers implement *features* individually, as an ongoing process. Browsers do not implement whole *specifications* in one go. Just because a feature is in a spec does not mean, and never has meant, it is ready to be used by authors.
Example: Microsoft only added support for CSS2's display:table (1998) in IE8 (2009), but had already implemented other CSS2 features in previous versions of IE.
So nothing to worry about - this is the way it has always been :) - it's just changing the standards process to more accurately reflect what actually happens in reality.
[edited by: mattur at 2:10 am (utc) on Jan 24, 2011]