It's been interesting to see how many places protocol buffers are now used by. I'm guessing a large fraction of companies use them internally without being too public about it, which is unfortunate because I've often shied away from using them as a Google-only thing.

It's remarkable that nothing better has replaced them, since they're a little old and crufty, but I guess most of the web startup community was happy enough with JSON. Plus, it's still hard to tell if proto2 or proto3 is the right version to build on long term.