Used the following SIMULTANEOUSLY, which means 2 sources.
Accomplished on a MacbookPro Retina with 2 thunderbolt ports
1x Intensity Shuttle for Thunderbolt
1x UltraStudio Mini Recorder
Both were detected by the Blackmagic preference pane AFTER I installed what appeared to be the same software for both. Seems that, even though Blackmagic names their software packages the same thing, there are still different versions to install for each Blackmagic item you try to hook up. To find the drivers for said devices, simply go to http://www.blackmagicdesign.com/support/
then select your OS and device and download the software.
Now going to test UltraStudio 3D with UltraStudio Mini Recorder to see if I can get 3 sources.