Hill's originally from a publishing and typography background rather than software development, so for a start it's a nice change of perspective. He's a very enthusiastic speaker, and as it happens he's also Scottish - he worked on The Scotsman in the days when it was still a credible newspaper.
What he's talking about is trying to improve typography and page layout on the web in order to improve online readability.
He's not a web expert per se - he's picking up standards-compliant HTML and CSS as he goes along - and if you're a web developer, you may have qualms about some aspects of what he's trying to do. For example, his preference for full-screen viewing goes counter to received wisdom about how web content should be designed, and it's fairly easy to find situations in which his sample pages don't work.
However, you should bear in mind that this is work in progress, and that while he's challenging some web assumptions, he really does know his stuff on readability, so it's worth hearing what he has to say. Look past the bits that immediately give you the grue!
The real substance is that Microsoft are opening up their previously proprietary font-embedding technology for the web, and making it clear they won't support the alternative font-linking solution - for reasons that are perfectly good if you believe that type designers deserve to earn a living. Ascender Corporation are explicitly throwing their weight behind this, and it's likely to be supported by others. Hopefully it will also be possible for the other browsers to implement support for font-embedding now that it's no longer proprietary.