I spoke to Dean Hachamovitch, General Manager of the Internet Explorer team at Microsoft, and used some of his comments in a piece for Guardian Technology. I’m pondering putting the whole transcript online.
…but what he didn’t say was, we’re actively working on it, we’re excited about it, we hope when it’s finished we will implement something in the future. He didn’t even go anywhere near that. He gave you a correct and politically astute answer.
Schroepfer was spot-on and I was impressed by his psychic powers, since he had not been present when I spoke to Hachamovitch. Microsoft has lots of experience in implementing languages with features similar to ES 4.0 and it seems to me that its reluctance to embrace it must be for strategic rather than technical reasons.