SPDY addresses some shortcomings in HTTP, but you will always have to be mindful of the amount of render blocking JavaScript and CSS loaded on your page, regardless of network protocol.

If you load large amounts of render blocking JS/CSS in the <head>, the browser must wait for it to finish downloading before it can render content in <body> to the screen.

To deliver a fast experience, keep the amount of JS/CSS needed to render the initial view to a minimum. Ideally, that'd be no JS, and just the CSS needed to style the content in the initial view. Then, once the initial view has rendered, load the JS and additional CSS needed for the rest of the app.

Looking forward to that!

Unfortunately the question then becomes, how long until all the major browsers support it? And once that happens, how long until the crowd not using the updated browsers is small enough that we can safely ignore them?

I suppose the auto-updating browser trend should help a lot with the latter issue.

SPDY (and thus HTTP2) is implemented and shipping in Chrome, Firefox, Internet Explorer 11 (except win7) and Opera. It's all ready and mod_spdy and the nginx spdy module are solid and available.

Wow, okay. I knew some of the bigger sites supported SPDY, but I didn't realize that the browsers outside of Chrome were already supporting SPDY (and HTTP2) as well.

So (pardon my ignorance, I googled a bit but didn't find very conclusive results), why isn't everyone using HTTP2/SPDY now? Because of IE < 11 and Safari?

Edit: Or maybe because of the SSL requirement? Edited again: For clarity.

Probably because the spec is not finalized yet - I bet once SPDY is essentially name changed to HTTP2 it will see wide adoption.

Don't even video games using image sprites for (non-network) performance benefits?