National Journal has the story, and Patently O has lots of good stuff for context.
Along similar lines, David Abrams and Polk Wagner have just posted an interesting new draft paper on one of the major questions addressed by the patent reform bill: Priority Rules: An Empirical Exploration of First-to-Invent Versus First-to-File. The paper offers an empirical analysis of the same law change in the Canadian patent system to get a sense of how it might work in the United States.