On AppengineJS

Looks really cool, but I wouldn't go so far as to classify NodeJS as a "toy" solution. Using your definition, Sinatra is a "toy" solution, as is default PHP. None of those have "deployment processes, multi version processes, system setup, server tuning, database scaling, backup processes, security policies, monitoring, profiling, admin console etc, etc." baked in either.

I think #3 needs to be expanded a bit. It seems to be saying less "javascript is good for web applications" as it is saying "the web is good for javascript web applications". There's a very fine distinction between those two statements. :-)

Maybe there's a grain of truth to it, but it doesn't particularly convince me fairly well. First of all, you're presuming that it's a good thing to share code on the client and server side. It turns out that there is such thing as reusing code too much. In particular, I don't like the idea that now not only do I have to worry about browser-specific hacks in my client-side code, but I have to also worry about browser-specific hacks in my server-side code as well.