For the last few months I've been working for Nexenta Systems on the next release of their free OS Nexenta Core Platform 4 (NCP4). NCP4 is pretty much a port of the base Debian Squeeze (not quite Debian Sid but certainly a step up from Ubuntu hardy!) packages onto Illumos with a few tweaks here and there to keep some compatibility with Solaris and NCP3. A lot of work has been done on fixing issues that were in NCP3 so I know this is going to be a great release and a stable foundation for the next StormOS.
One thing that we still have to work out is how we will handle 64bit stuff. I had originally wanted to create a new 'solaris-amd64' branch of StormOS but that is starting to look like a bad idea. Illumos is capable of booting up in either 32 or 64bit mode based on the hardware it is running on, so it kind of makes sense for everything else sitting on top to do that too. What I'm looking into instead is adding support for Fat binaries (Universal binaries in Mac speak) and now that FatELF has been released into the public domain that should be easy.