The WRF version 3.7 has been released on April 17th. All updates are given on WRF model page details of UCAR website.
New version of WRF model available : 3.7
New options for physics, PBL, soil, dynamics and memory requirement imorovements have been made. For a typical run, the memory could be down 30%. WRF version 3.7 can use wrfinput and wrfbdy files from version 3.6. Note that the VEGPARM.TBL in run/ is updated, and must be used with 3.7 code.
Check our page (in french) about WRF.