I'm using cluster, crypto, express, memcached, mysql, and mysql-pool in production and they have worked flawlessly for a node deployment that serves a pretty busy JSON API (200-300 reqs a sec on average).
Node.JS has a great community that is writing many great modules, no doubt. But the community is very young and almost by definition many of the modules are immature.
This can be very enjoyable from an engineering perspective (you get to write and hack on things that you would not otherwise), but can also slow down the process of building things since you do end up having to reinvent the wheel at times.
With your response in mind - I don't see Node being mature enough (yet) to solely support an end-to-end large scale Web property. But, for serving up API content from Memcache/MySQL - it is blazing fast with minimal footprint. On our stack - we run Node right on our existing Apache Web servers (behind haproxy).