I am going to make a prediction that XXX on Rails (where XXX is Ruby, PHP, Groovy, Java) MVC frameworks are going to see a rapid decline in the coming years.  Node.js will be the replacement.

The reason? Every web application developer knows Javascript. In fact in my mind your not a Web App developer unless you know Javascript.

Javascript is the Lingua Franca of the web world it is easily becoming the Lingua Franca of the mobile world also (Appcelerator, PhoneGap, Sencha touch etc…).

Evocatus is uses an enormous amount of Javascript (not in terms of LOC but in terms of logic). Only our recommendation engine, syndication, and persistence are written in Java. Almost all of this could be written in Javascript. Not to mention almost all the services we rely have some sort of JSON API.

Node.js will also succeed similar to how PHP succeeded in the Web 1.0 world: Ultra low barrier of entry. Ignoring what PHP is today it was originally just HTML with some additional markup and it was because of that that it had such rapid adoption. Now with Pushstate being supported in most browsers you can share your frontend view logic with your backend view logic and should still work legacy browsers if you use node.js. Thats pretty cool!

So whats the future of other language technologies? Well I expect to still see Java, Scala, and .NET, C and maybe even Haskell being used for intense number crunching or where performance is critically important.