Watching the game last night one of the TSN commentator's, I believe Suitor, mentioned he believes that if a team gives up a safety they should have to kick-off from their own 20 yard line, as opposed to the current rule of kicking off from the 35 or the team choosing to take the ball from their own 35.
Personally I think this would be a great idea (coupled with the option of taking the ball at your own 50 yard line). Right now the safety is used as strategy, to change field position. Unfortunately it is being used to often, and it has become to easy of a decision to just give up the safety.
Change the kick-off position and make the coaches think more when giving up a safety. Also putting emphasis on a great defensive stop deep in their opponents territory.