Statistics gets interesting with big data. I see some companies, SAS, SPSS(now an IBM company) are trying to integrate Hadoop to their products, for the big data challenge. What do you mean by Predicative Analysis on Hadoop? The algorithms will be implemented in a MapReduce way? How about some algorithms not compatible with this paradise?
Predictive analytics is an umbrella term for things like data mining and machine learning. This chapter mostly covers Mahout, and a list of the algorithms that is supports can be seen here: https://cwiki.apache.org/MAHOUT/algorithms.html