Full support for... a test suite (Score 2, Insightful)

Passing a single test suite isn't exactly the same thing as supporting the whole standard perfectly. Test suites, by their very nature, only test select subsets of the standard. A single general test suite cannot expose every possible bug in every feature. On top of that, this test suite only covers the selectors, which is a fairly simple and straight-forward part of the spec. Heck, even Internet Explorer supports a bunch of CSS 3 selectors. It's one thing to claim full support for selectors; it's quite different to claim that pseudo-elements with table display values in nested floats with negative margins always work correctly. It's great to see progress, and Firefox and Opera are both impressively close to full support for the current CSS 2.1 specification, but let's not exaggerate the situation. They both still have a lot of work to do (as does Safari, which was clearly behind overall in version 2.x and is likely still a bit so in version 3).