I had written about it before, that the Exchange 2010 RTM support ends on Oct 11, 2011 (yesterday), read here. Make sure that you have upgraded all your 2010 servers to SP1 before you log a call with Microsoft support team! Ideally, you should have all the update rollups installed as well (latest being UR5, at the time of writing).
Every exchange admin should be familiar with the screen below by now, if not you should 
