The difference is this time lessons have been learned. Browser vendors are now actively working together. The HTML5 project has done a great job in collecting a

The difference is this time lessons have been learned. Browser vendors are now actively working together. The HTML5 project has done a great job in collecting and codifying real world behaviour. No browser will ever implement the current spec because it's shifting sand. A smaller but stabilised spec that can be extended is much better for everybody who isn't a major browser vendor.