I am just speculating, but I am betting that Biron was worth a 1rst, 3rd, and 5th rounder. In turn, a 3rd and 5th rounder plus Rory Fitzpatrick could have landed us a decent blueliner. Mika for a 2nd rounder is a pretty conservative move. I was hoping for something a little more bold.
Mostly I was hoping for an excuse to send Fitzpatrick out of town.