Ryan Paul has the details at Ars. Nuanti is making a high speed decoder for Ogg Theora video and Ogg Vorbis video. The catch is this is a component for Silverlight, Microsoft’s competitive technology aimed at Flash.
I suppose Ryan is right in his conclusion, this is actually a pretty good thing for Internet Explorer users who are already using Microsoft technologies. My initial revulsion is also abated when I remember that both Firefox and Chrome already sport native support for both codecs.
I guess that also makes sense of his observation that users won’t have to install any additional software or plugins. If you assume Internet Explorer already bundled with Silverlight, then this could indeed be a seamless way to spread the formats. Nuanti is even looking to open the sources for the component.