I started discussion thread for a new R package to expose MLlib pipelines in R. 

To summarize we will work on utilities to generate R wrappers for MLlib pipeline API for a new R package. This will lower the burden for exposing new API in future. 

Following the SPIP process, I am proposing the SPIP for a vote.

+1: Let's go ahead and implement the SPIP.
+0: Don't really care.
-1: I do not think this is a good idea for the following reasons.