Just released a somewhat working version of Zoned Player Names.
The addon enables/disables player names automatically, based on the kind of zone you're in. It's disabled in friendly zones and istnances, but enabled in battlegrounds, contested zones etc.
Read more and download it here:
http://www.wowinterface.com/download...fo.php?id=6286
I'm gonna make it niftier in teh future, such as making it a bit more configurable (which zones to do what in, for instance) and also have some sort of gui config. And make it work on PvE servers.