Last weekend I installed SP2 and UR3 onto our Exchange 2010 CAS and Hub Transport servers, along with the mailbox server. Mail flow seemed fine afterwards and I was able to send and receive emails, but sometime over the weekend two services stopped. I started the services Monday morning before everyone got it, but some automated reports ended up not running over the weekend.
Solution 1: I put a powershell script in place that I found online that monitors the Exchange Servers and emails me daily at 8PM through a scheduled task. I will eventually be modifying it to show the hard drive space of all the partitions.
Solution 2: There is a command you can run in the Exchange Management Shell that will show you the status of all the Exchange Services on each server, and show which are running, and which are not. This command is Test-ServicesHealth.