My comment is here.
Note this debate is not only about the merits of different versions of Javascript/ECMAScript. It is also about power and responsibility. However you spin it, and however far Adobe and/or Microsoft succeed with Flash/Silverlight/AIR, I think we can agree that the browser has an important role for the foreseeable future. It is also likely (though less certain, I guess) that Internet Explorer will continue to have a large market share. The company does have a responsibility not to hold back the Web, and that surely includes not obstructing the evolution of a high-performance Javascript runtime.
It is disappointing that Microsoft says so little about IE8, presuming it exists. If the company sticks by its undertaking to leave no more than two years between IE releases, we should expect it no later than October 2008, less than one year away. It would help web developers to know more about what will be in it.