As you probably already know, the MPI-3.0 document was published in September of 2012.
We even got a new logo for MPI-3. Woo hoo!
The MPI Forum has been busy working on both errata to MPI-3.0 (which will be collated and published as "MPI-3.1") and all-new functionality for MPI-4.0.
The current plan is to finalize all errata and outstanding issues for MPI-3.1 in our December 2014 meeting (i.e., in the post-Supercomputing lull). This means that we can vote on the final MPI-3.1 document at the next MPI Forum meeting in March 2015.
MPI is sometimes criticized for being "slow" in development. Why on earth would it take 2 years to formalize errata from the MPI-3.0 document into an MPI-3.1 document?
The answer is (at least) twofold:
MPI-4 is still "in the works". Big New Things, such as endpoints and fault tolerant behavior is still under active development. MPI-4 is still a ways off, so it's a bit early to start making predictions about what will/will not be included.