The community for Halo Full Version and Custom Edition is still alive and it would only increase if it were to be added to the Steam marketplace and server lists. Gamespy is shutting down their servers so Halo needs to be saved! There is roughly 10k~ unique players that still play the game online and a percentage of that 10k~ still play competitively. Any form of support is welcomed!
If anything is to happen, at minimum a master server update or a new master server by steam or any other affiliated company would work as well!
Also, if you have a server on Halo FV or CE, please put the link to the petition in your message's of the day to raise awareness!