This message has been directly copied from the pixelmonmod website:
It's Been a Gréat Ride
With much sadness, but keeping all our fond memories, we must announce that Pixelmon is ending its development. We have had a great time making this mod and creating such a wonderful community but after a request from the Pokémon company we will be shutting our doors. I'm sorry for the disappointment this will cause but let's remember all the great times we had playing Pixelmon, discussing Pokémon, making awesome things inside this mod and everything else that we've done.
All good things come to an end eventually and now is our time. However there are always more things to do, to be a part of and to enjoy. Keep going out there to find fun projects to be a part of and other great things to invest your time and enthusiasm into.
The Pixelmon Team
This effectively means that development of the mod has stopped, unsure is what is going to happen to servers at this current version. At this point we have no means of discontinuing the server unless it will be actively enforced. Leave a message either here or on the pixelmonmod website and state your opinion.