Google prediction API: What training/prediction methods Google Prediction API employs? The details of the Google Prediction API are on this page, but I am not able to find any details about the prediction algorithms running behind the API. 

So far I have gathered that they let you provide your preprocessing steps in PMML format.
If you take a look over the specifications of PMML which you can find here you can see on the left menu what options you have (like ModelTree, NaiveBayes, Neural Nets and so on).