Looking at UFA defensemen this year, the pickings are pretty slim:
http://www.capgeek.com/free-agents/?...D&fa_type_id=2
I think signing him for 3 years (ideal would be 2-years, but I think he could get at least 3 elsewhere) might be the best option to (a) avoid overpaying for someone older and/or worse and (b) avoid rushing the likes of Wotherspoon et al.
A year ago if someone would have told me that the Flames have extended Stajan and should extend Butler, I would have laughed hysterically. Both have had good years and are needed to bridge during the rebuild.