What I see in practice is the exact opposite. Everyone writing about "what is possible" with JavaScript (custom 3d rendering engine for every website!), very few people are concerned about architectural and practical issues of it all.

Web applications are only going to get faster, and if you want to keep up, you're going to have to do implement modern solutions like Battlelog and Google+ do.

I can envision a time when full page refreshes are the exception and that isn't a bad thing.

Full page refreshes are not what makes web applications slow. I used to browse the web on 133MHz computer over a mediocre modem connection. Today, despite all these promises of speed, many JS-heavy websites seriously lag on anything slower than 1.5MBps and 2GHz dual-core. (Try browsing via Kindle.)