I first heard about Blaze from NumPy’s original developer’s blog back in December 2012. Recently InformationWeek announced that DARPA was funding the project to the tune of $3 million dollars to get some big data libraries written for Python. There will be two new projects, Blaze and Bokeh. Blaze will be an extension of NumPy and SciPy and make those libraries big data friendly. The Bokeh project will be for big data visualization.
Blaze will be open source. You can read more about it here. I was unable to find a specific link to the Bokeh project.