Never found anything to post with that was new before but I haven't seen this about anywhere.
Basically if the opposing faction is neutral to you (PvE servers, PvP servers in sanctuaries), you can inspect them.
The thing is if their level ?? you would normally have no idea what level they were, you could guess but not get the exact one (from the gear their in). However if they have an heirloom item the level of it is still displayed in brackets as it would be normally.
As I said the usefulness of this is fairly limited, but if you're on a low level alt could just give you a rough idea of what level that opponent is that's attacking the crossroads etc without needing to get the main down. If anyone else can think of a more constructive use for this then great!