The company I worked for had this arrangement during the Gulf War downturn.
I was pleased to get command experience , welcomed the extra money and enjoyed flying with co-pilots who I would otherwise not have known.
As far as CRM issues are concerned it was a lesson in diplomacy fom both side once the summer period ended.
If you are a professional aviator then there will be no problems, enjoy the summer and who knows maybe the economy will have picked up and you stay where you are , or at worst your company goes down the pan and you have the experience to get a command elsewhere.
It is also rather like the issue of pay cuts , enforced unpaid leave, the airlines really do not know what is around the corner for summer 2009 , they are hedging their bets and trying to hang on to as many crews as possible to take advantage of any other failures.