Machine Learning in the Cloud, with TensorFlow
googleresearch.blogspot.com
googleresearch.blogspot.com
Disclosure: I work on Compute Engine.
Damn you time! I need more of you!
The same question was asked earlier of the Vision API, with the same answer: https://news.ycombinator.com/item?id=11128444
At a high level, you can think of it as having mostly the same properties as if you rented a bunch of GCE machines (or AWS machines) and ran TensorFlow on them, with your data stored in GCS (or S3 or whatever). The difference is that Cloud ML handles the scaling pain for you -- managing the machines, starting and keeping tasks running, load balancing, etc.
(disclaimer: I'm working on TensorFlow, not Cloud ML.)