Earlier today (~11am GMT+3) the MPI Forum ratified the final PDF of the MPI Standard Version 2.2. Other than a “No” vote from NEC the vote was unanimous in favor of accepting it. As I mentioned before this version of the MPI Standard contains many clarifications and corrections as well as several new features. The Change-Log (Annex B) contains a concise list of the relevant functionality changes.
Bill Gropp (the MPI-2.2 chair) is currently out of internet range, so the official document isn’t yet posted on the normal MPI Documents website. In the mean time I’ve posted an unofficial version here that you can download. I imagine that the official document should be up by Monday.
(Update (2009-09-05): The official MPI-2.2 document has been posted.)
MPICH2 should support these new clarifications and features in a release before the end of October (possibly sooner). All but one of them (ticket #33, the MPI_Dist_graph_* functions) are implemented already on the SVN trunk if you are so inclined to play with MPI-2.2.