It is probably too large for them to be able to determine if it can be efficiently implemented in DirectX with hardware acceleration. In order to know that, they pretty much have to implement the whole thing and see. And, if they find things that are poor performing (i.e. its primitives do not line up with DirectX's primitives), they're going to push for changes to the spec to make it efficiently implementable. But, those change proposals are likely to fought by the other browser makers.
Also, I believe Adobe is likely to ask for changes to the <canvas> specification too.
Plus, <canvas> is not that important if you have a high performance SVG implementation.
Finally, <canvas> creates a situation where animated advertising cannot be easily distinguished from other content and cannot be separately blocked from other, useful, Javascript on the page.
So, I think there's more uncertainty regarding the <canvas> specification than people might expect. It makes perfect sense for everything to become more clear before committing to support it, considering Microsoft's very generous support and backwards-compatibility guarantees to its customers.
Why wouldn't they support this? With their share of the browser market constantly decreasing do they really want a large amount of websites taking advantage of the canvas in the future throwing up a not compatible with IE and links to download another browser?
IE6 is proof that many will painstakingly support IE instead of just throwing up a "not compatible" message and link to a different browser. Well, not until 5 or 6 years after the release date anyway. So why would they support new standards? :(
Glad to be part of a group which made the decision that having people install a browser that supports canvas is not a too excessive requirement. For years people have force users to use IE6 (and still do). It's time we force them to install a browser with the features we need.
Would you refer to someone as a Christian Evangelist if they said "Have you read the bible? That's a big book. And there's some crazy stuff in there. I mean we'll think about following it, but we'd rather just follow half of it really to the letter"?
Given how much effort he puts into dissing web standards the scare quotes seem appropriate.
I have read primary sources on various Microsoft blogs saying almost exactly the same thing about a variety of standards (web and otherwise) over a period of years. I have no reason to doubt The Register reporting in this case. This is not in the same league as a tabloid claiming that Elvis and Bigfoot had a lovechild. It is expected that Microsoft will trash-talk standards even, or especially, as they are forced to implement them by market forces.
