Depends on who you want to believe.

A recent Digg poll showed that many people are incapable of escaping using Internet Explorer i.e. on closed systems or at work, so it's no surprise IE still has as lingering percentage of marketshare.

As Microsoft will be one of the foremost implementers of HTML5 (with IE still having a majority of the market share, unfortunately) it's a very good thing that Microsoft has decided to become involved in the spec rather than leaving it up to its competitors, giving it some notion of responsibility in how the spec turns out.

It seems some of the comments are looking for simple justification (such as why the >aside< tag exists, use cases, etc.) as well as more clear definitions of other new features (including their very own original contentEditable feature), and rather than "influence the spec" as the summary claims, it looks like the IE team is looking critically at how a completely new entity would approach HTML5 (not having had the vested involvement other browser makers have).

What remains to be seen, however, is if the IE team responds to the working group's justification and follows through on the spec, or if it only trusts its own judgment and implements the parts it deems "necessary". This is still the dogged-slow Microsoft team, and in spite of great improvements in IE7 and IE8, reporting issues in the spec during the Last Call stage is not an encouraging insight to their commitment to making HTML5 happen.

I believe they already do, for the most part. HTML5 parsing rules were mostly reverse-engineered from existing browsers' HTML parsing rules, which are more or less consistent across modern browsers, so it's only documenting what most existing browsers already do.

What the spec is defining is a limited subset of an SGML-like language (whose entire parsing rules, if incorporated into HTML, would span for pages) and how to transform it into a DOM. It isn't mandating any new parser rules, it only documents them for the benefit of new implementations of the spec, and to align what minor variations there are between browser parsing models together. Compared to SGML rules (of which HTML 4.01 is technically a subset), this is a great improvement.

This is exactly what CSS is designed for, presentation. The CSS3 Paged Media module already defines a number of the properties and settings you're going for. It even includes positions such as @bottom-center to allow you to position footnotes and references. The only thing missing is a way to mark this up in HTML, which could easily be done with anchors and the longdesc attribute, coupled with the CSS content: property. What you're looking for is a CSS3 enabled browser, not a new specification.

Don't install it.

Well, the fennec is nocturnal...