Effective May 31, 2014, GameSpy will cease providing all hosted services for all games still using GameSpy.Since Halo PC's server browser function and all rented servers use said api, this method will no longer work. However it remains to be seen if the Direct IP method of joining a server will work after this date. However, it is a somewhat sad day especially given the history of this community.
If you have any questions about how this impacts your favorite title please contact the game’s publisher for more information.
Thanks for a great ride!
To recap, here is the server status for various Halo FPS games:
Halo 1 PC: Running (Will be discontinued on 5/31/14)
Halo 2 PC: Running (For who knows how long)
Halo 2 XBL: Discontinued
Halo 3: Running
Halo: Reach: Running
Halo 4: Running
We can certainly see about a last hurrah or so.