Google has announced that App Engine now supports node.js projects, but the news is not quite what it seems.
What's available now is not a true platform-as-a-service offering on App Engine like the existing Python and Go runtimes. Instead, the node.js offering is running inside their App Engine "flexible environment". This flexible environment is based on managed VMs built on top of Google Compute Engine.
This hybrid environment eliminates the need for developers to manipulate virtual machines as in a traditional infrastructure-as-a-service environment. However, because the underlying code is running on Compute Engine, developers can SSH into the VM instances if they need to. App Engine will apply critical patches, automatically scale based on load, and periodically restart instances.
Google has provided a number of resources to get started as well as some samples. One noteworthy feature is the ability to use Google Cloud Debugger to debug the node.js code live, in production.
On a Hacker News discussion, user plexicle was dismayed that this wasn't true App Engine support:
I want real GAE. Not managed VMs. I want to be able to spin up a quick GAE version on a deploy, and if it doesn't get the traffic to scale up, then it just sits there and doesn't cost me anything. I'm glad that they are pushing Node and I'm a HUGE fan of the Google Cloud. I just really want Node as a native GAE thing.
While this work is a step in the right direction, Google still has work to do in order to provide a pure platform-as-a-service option for node.js developers.