I see that over the past few days the hype for "Heartbleed Security Vulnerability" has increased. Several sites administrators have take actions to prevent their servers from being compromised.
Stack Exchange has also taken few steps to protect its users' data. Some of the methods have been mentioned here
Isn't it a good idea to logout all users from the network and let them signin again so that all the keys have been updated?
SoundCloud is doing this and I guess StackOverFlow and other Stack Exchange sites should take this into consideration. It can help.