Open Source Solaris
Excerpt from http://www.infoworld.com/article/04/04/30/HNsolarisgpl_1.html:
Sun Microsystems Inc. may be selling servers running Linux, but that doesn't mean it is cutting back on the evolution of Solaris. Among its plans, the company is considering offering a free, open source version of its flagship operating system, said Jonathan Schwartz, the company's recently appointed president and chief operating officer.
Also see the associated slashdottery at http://slashdot.org/articles/04/05/01/1235209.shtml
Boy, am I interested to see how this plays out...