Microsoft has released SP2 for Windows 2008 server. Now the question is – Will Exchange 2007 SP1 run on Windows 2008 SP2? Yes, it will. It will be the same for Exchange 2007 SP2 as well.
Another thing to note is that you need atleast Exchange 2007 SP1 to install it successfully on a Windows 2008 Server (SP2 or not)!