There is a project coming up - railwayjs. I hope it changes the way people use nodejs!
Anyway, writing Rails for Node won't be anything revolutionary, it would just be... Rails on a different platform. Frankly lots of developers including myself prefer these smaller frameworks, sure some things might be a bit slower to get started with but ultimately you're not fighting a framework, it's just another block of lego.
I used Drupal for about 3 or 4 years, and you can get things going much faster than Rails even, but you'll spend a lot of time fighting the thing.