There was a very good documentary just the other day (probably on History Channel) about the Enterprise(s).
Not having ever paid a ton of attention, I was surprised to hear that this is the 4th ship so named by the Navy - I guess there'll always be a USS Enterprise. I think the program said this one's due to retire in something like 2013.
The current USS Enterprise is the first nuclear powered carrier that the Navy had. The next one was the USS Nimitz.