Probably this will only come with the scriptable GUI which is planned for 0.9 or 1.0. Until it's implemented, you can use the
dpmaster serverlist for that, just click the PLAYERS label on the top and it will sort the list by the players. There is already a solution for launching OA from such a list, take a look at
OACON. Currently it's Windows only, and the player sorting is not implemented, but I'm sure Diho and RMF will implement this soon. Also I'm working on a FireFox plugin which can launch OA directly from dpmaster, but so far it's in a proof of concept state, it still needs a lot of work (release probably by the end of March).