I'm making a new blog for a startup who want a similar infinite scrolling effect to http://qz.com/
It also needs to include the URL changing as seen within the previously mentioned link.
For the life of me I can't figure out how it's done, I think it uses the HTML5 History API, but I also had it working in internet explorer so maybe it doesn't?
I would be incredibly grateful if someone could give me some pointers on how to make this work (using WordPress).
You can use infinite scroll to your WordPress theme by add some functions. And also you can activate this feature by using jetpack plugin. Basically it's using AJAX.