The serious Serious Sam lovers at Seriously! have word on efforts that are underway to save multiplayer support in Serious Sam 2 from the effects of the imminent GameSpy shutdown. They have details on master server workaround that's already available, and word on plans to patch semi-official Steamworks support into the shooter sequel:

Two solutions for the GameSpy problem are going to be available for Serious Sam 2. The first one is available now: the replacement master server project by [Rocketers] Alex:

The second is that Angelo, from Alligator Pit, is working on implementing Steamworks into Serious Sam 2 as a sort of official/unofficial patch.

Good news for Sam 2 fans!