Ура, node.js оказался более масштабируемым для comet-приложения, чем решение на Java + JBoss Netty:

"We have rewritten to node.js from Java+JBoss Netty, because the old solution had scalability problems. We have also been able to build a very sophisticated messaging system given JavaScript expressiveness and the simplicity of node.js. Generally, we have found node.js and V8 very impressive - and it uses about 10 times less memory than Java+Netty did. The bottom line is if you implement anything comet related - - try to use node.js!"