How about some Coliseum PvE?

[Noxifer]

I would add in PvP as well for the salt in the soup. :-)

Like 4 man Coliseum

Round 1 PvE
Round 2 PvP
Round 3 PvE
Round 4 PvP
Round 5 PvE
and so on.

For entering Coliseum it is mandatory to form a group of Tank, Heal, DD, DD.
During Coliseum it will NOT be possible to change the chosen class.

I wouldn't like it if it mixed PvE and PvP into the same "instance", so to speak. That would alienate those who like PvE but not PvP. Better to have two categories of entry, in that case. It'd make it easier to award PvP exp for the PvP category of it, too.