With the OpenIndiana 2016.10 release they've switched to MATE 1.14 by default rather than the GNOME desktop when doing a GUI installation. OpenIndiana 2016.10 also has Intel KMS support ported from Oracle Solaris, Python 2.7 is now the default system Python, Sun SSH was removed, and they are no longer advertising support for 32-bit systems.
OpenIndiana 2016.10 is making use of GCC 4.9 as the primary compiler but GCC 5.4 is a new compiler option. This release also adds PHP 7.0, Golang 1.6, NVIDIA 340.96, and various other package updates.
More details on OpenIndiana 2016.10 via the release notes. I'll be trying it out on some of my test systems to see if I can get it running (I haven't had luck in the past year or two with finding hardware playing nicely with OpenIndiana) and if so will run some fresh Linux vs. OI benchmarks.