Moses Kaumatule will not be on the team this fall. He goes into the MTC September 26th to serve in the California Oakland/San Fran Mission. He'll miss three years and rejoin the team for the 2015 season.
Tuni Kanuch will not be back until the 2013 season. He left December 29, 2010 to serve in the California San Diego Mission.
As you mentioned, Austin Hoyt will likely begin his Cougar career as an Offensive Lineman.
Remington Peck returned home in April from his mission to Rochester, New York and will rejoin the team in the fall.
Walk-on Mason Higham returns in July from a mission to Brisbane, Australia and may rejoin the team.
Also, new walk-on Tyson Brook from Connell, Washington is expected to join the team this fall (http://www.thenewstribune.com/2012/02/01/v-lite/2007432/ewu-nabs-cbbn-trio.html).
Finally, it's a longshot, but I still show Thomas Bryson as a longshot to rejoin the team. I've heard nothing definitive, but I know he's been practicing with Snow College and he'll most likely play there, at least for the 2012 season.