Over the weekend I heard from a frustrated developer that AMD has reportedly conceded in their support for Open64. AMD has been a big backer to Open64 in years prior as an alternative to using the GNU Compiler Collection. AMD has their own Open64 fork where they have support for the latest AMD CPU features. The most recent release of AMD's x86 Open64 compiler is version 18.104.22.168 and this series introduced AMD "Piledriver" Family 15h support, AVX/XOP/FMA3/FMA4/BMI/TBM/F16C intrincs, improved performance, and was updated against Open64.net trunk.
This latest AMD Open64 22.214.171.124 release was made available in March and since then there hasn't been any updates. The Open64 compiler also only supports Piledriver while GCC already supports AMD's Steamroller and Jaguar processors.
Beyond not much activity or use out of AMD's Open64 compiler, the upstream Open64.net project is not vibrant by any means compared to GCC or LLVM.
The most recent Open64.net compiler release was version 5.0 and it came in November of 2011. Since Open64.net 5.0, there hasn't been any official release. Both the user and developer mailing lists for Open64.net are also rather dormant with only a handful of messages on each list for the 2013 calendar year. The Open64 Wiki also lacks any new content.
Overall, there hasn't been much out of Open64.net in about two years. We'll update if we hear anything different on the matter or see a new release in the coming months, but don't hold your breath.