So yeah, that is happening
Activision: "Activision won't be affected."
Bohemia: "Yes, we are aware of GameSpy issue and we are very near to [finding] some suitable solution, but I cant tell you more details at the moment."
Capcom: "There are a few titles for which Capcom utilizes GameSpy’s matchmaking services for online gameplay. We are evaluating migration solutions and will have more information in the near future. Please check back on www.capcom-unity.com for updates."
Other companies haven't commented yet