According to Return Path and Next Web, LinkedIn was hacked today and the bad guys were able to steal passwords for about 4% of their userbase, affecting approximately 6.5 million accounts. Are you one of that 4%? Let's not find out; go change your LinkedIn password as soon as possible. Also, if you used that same password elsewhere, be sure to change your password on those other sites as well.
This perhaps isn't specifically a deliverability-related event, but everybody professional I know in the email space seems to utilize LinkedIn heavily, so I wanted to help get the word out.