This is super awesome. I've been meaning to transition our folks to Flexbox for web apps that targets mostly modern browsers. The main objections are, of course, browser support. This is a good start for me to take more informed decision. :-)
Just be aware, figuring out workarounds for some of these flexbox bugs in the wild can be a bit tricky - I ran into the min-height one not being respected on all browsers but Chrome, but I was able to find a different workaround in order to get it to play nice on all browsers.
