IHMO, a "spectate" option would be great for this game! Spectating can greatly enhance the multiplayer aspect, and is (going to be) part of RTS games like the new C&C and starcraft2. So why not Sins? Think up some clever connection scheme, like making the ICO server host for spectators, and delay spectating by 5 mins to prevent cheating. I am sure there are a lot of possibilities to make this happen.
my 2 cents,
AntiBody