My initial reaction was acquihire. Though given their recent improvements to Pages [1], this acquisition could mean a push into the Easel market space.

1: http://pages.github.com/

EDIT: Just to point out why this is a big deal - What percentage of new sites are mostly static, presentational? Probably a slim minority. Whilst Github can't code your site for you (yet?), giving you the tools to develop your app layer and frontend - with some as-of-yet seen integration tools? - those are some very large slices of the pie. Don't forget Github pages is currently free too, perhaps there'll be a paid tier for dynamic sites.