According to slashdot this morning, Sun has announced the open sourcing of the Solaris operating system. From what I could glean from the referenced articles, this covers the x86 version of the operating system, and while security fixes will be supplied for the free version, receiving bug fixes will cost you $120 per processor, per year, with additional support plans going up from there.
I personally hate the idea of paying for anything “per cpu, per year”. I like models where you can pay for support for a machine, no matter how many processors the machine has. This pricing model alone would keep me from actually using Solaris in lieu of a competing Linux distribution.