Those students in the class paying attention may have noticed that Solaris on amd64 is quietly coming to life. While it's been thriving in development for a while now, it's finally flexing its muscles publicly. A few sightings at blogs.sun.com:
As for myself, I have been pitching in with amd64 development here and there; mostly getting the userland debugging tools functional. Recently, I ported ZFS to amd64 - which was really only a bunch of Makefile and compiler changes (the joys of porting a well-designed 64-bit capable subsystem). There are, of course, others doing most of the work - Bryan, Bart, and the many anonymous team members too busy doing the heavy lifting to maintain an external blog.
For you Solaris Express junkies out there, amd64 support will probably not be available in the next release. Look for it in a later release or S10 FCS.
All told, amd64 support is pretty exciting. The hardware is blazingly fast (and cheap!), and we finally have an OS that can really take advantage of all that it has to give. With our resident hardware genius behind the wheel of our amd64 platforms, we're going to be coming out with some absolutely killer hardware. 2005 will be an interesting year...