I recently saw a question from the field regarding Agent installation:
"I'm trying to manage a group of servers with Ops Center. They use Java 1.5; is that going to be a problem?"
No, it shouldn't be. The Ops Center Agent uses Java 1.6, but it will install Java 1.6 if it's not already there. Java 1.5 and 1.6 can coexist on your systems. As long as Ops Center can get to Java 1.6 in the default location, it should work fine.