The roll-out of Groundwater Vistas 6 and AquiferWin32/Winflow Version 4 has gone very well. Thanks to all of the "early adopters" out there! This is always a nervous time for us when a new version is released but these have been quite stable. There have been a couple minor fixes, which I will report on later, but no major problems. The biggest surprise to me has been the popularity of 64-bit computing.
I'd also like to repeat that MODFLOW-NWT looks like it should be released by the USGS any day now. As I mentioned previously, we will post an update to Groundwater Vistas as soon as that occurs. And we are still planning on releasing a version of MODFLOW-USG at the MODFLOW2011 conference. Thanks to Sorab Panday for that!