It would be useful if spark would provide support the evaluation of PMML models (http://www.dmg.org/v4-2/GeneralStructure.html).
This would allow to use analytical models that were created with a statistical modeling tool like R, SAS, SPSS, etc. with Spark (MLib) which would perform the actual model evaluation for a given input tuple. The PMML model would then just contain the "parameterization" of an analytical model.
Other projects like JPMML-Evaluator do a similar thing.