Given the push on player safety including via the pressures of mounting evidence against the NFL in litigation and very soon the new public interest via our first national health care for all starting in 2014, expect major changes to the rules including especially for the sake of player safety including more to protect the "defenseless" player and also new rules to protect defensive players.
Predictably, already I see the draft stock of any given college safety dropping further than ever too. If a college player in the secondary can't run better than a 4.50 in the 40 and cannot backpedal to cover as corner and doesn't have superior agility for change of direction, well one's place in pro football is severely limited and even then one might be out of the NFL within three years when they can be replaced for cheaper unless a core player at SS. Some of those guys are able to make the move to free safety though. Also the shorter the player at corner, the faster he must be able to run as now the corners are getting taller too.
There is an exception to this trend for the safety position for any given large strong safety with some agility and mobility such as Kam Chancellor of the Seahawks and some other notable names like Bernard Pollard of Baltimore, Roman Harper of New Orleans, and Morgan Burnett of Green Bay. These types of guys are far less common via college any more though.
When you watch Ed Reed play again this weekend, you will be looking at the end of an era at the position as otherwise Troy Polamalu will linger. Ed Reed in all senses is still the best safety in the game at age 34 but has quite an injury history and rumour has it that he will follow Ray Lewis. Earl Lewis of the Seahawks might be the heir to Ed Reed but it's way too early still, and Mark Barron here in Tampa Bay is looking great after his rookie year.