Multiple-unit Train ~ Interesting Five Locomotive Set-up

Union Pacific Multiple-unit Train... I caught this very interesting power unit set-up the morning of June 28, 2012 heading out of Northfield, Minnesota. Snapped some still images at a crossing in town and video further up the line. Any comments on engine types and why the interesting line would be appreciated.

[TNS]

This is likely the most epic lashup I have ever seen, an ex SP & CNW, and a UPY! How rare is that and how epic is that