Belated update note
A few weeks ago I made some updates to WCIU, but forgot to mention them in this update feed.
Chrome 3 is now the "stable" build, and Chrome 4 has been added for the Future. Chrome 3 supports the "audio" element, and Chrome 4 will finally have anti-aliased rounded corners.
Also all features for Firefox 3.6 have now been decided on, so some of the previously mentioned features (SVG-in-CSS, SVG SMIL, etc) have been moved to Firefox 3.7/4.0.
A new "unofficial" feature has also been added to the page: "3D Canvas graphics / WebGL", which has been gaining popularity.
Thanks goes to Magne Andersson for the Firefox info and the reminder to update this feed.