I don't see any real need to give any more than 1 year.
With the view that 2014 will be a stronger draft we need to be in position to make significant changes if they are warranted.
While I'm not sure of the contract status of every player on the list, we certainly have Gia going at the end of 2014 as well as setting up to allow us to drop off a few others.
These would include Howard, Tutt, probably Pearce plus any or all of this years retained/upgraded rookies. We would also probably need Williams to get through the year to stay on the list.
This would give the scope to turnover 8 to 10 players next year and they would be well aware of the need to prove they are worthy of retention.