I'd be curious which things were missing in Node. I realise gratuitous detail doesn't make for a great blog post but if Node.js is missing things that stopped development of an app it would be useful for the Node community to know what they are.

Mentioning "immature packages" and "testing" is fine, but I'd really like to know what makes testing on RoR better than, say, testing with Mocha.

I'd also be really interested in the experiences of trying to cache with Node. I think while it's possible to do it's definitely a place that could be improved.