Note that in the image, content on the same server downloads async, but downloading appears to be synchronous when you switch between servers.
Clarification: HTTP 2.0 allows for multiple simultaneous sockets. The question is, "does that mean multiple sockets from multiple IP addresses simultaneously or only from a single IP address?" The waterfall diagram appears to say only from a single IP address at a time.
Additional info: All of the fonts are downloaded simultaneously, even though they come from two different servers. I've even verified that the request start time since beginning matches. See the three lines above the image section.