Deadpool and a host of other Activision published Marvel titles have been pulled from Steam, PSN and Xbox Live confirms Activision's community manager Dan Amrich on Twitter. The titles that include Spider-Man: Friend or Foe, Spider-Man: Web of Shadows, Spider-Man: Shattered Dimensions, Spider-Man: Edge of Time, X-Men: The Official Game, X-Men Destiny and X-Men Origins: Wolverine.
One possible reason for this could be that the licence agreement between Activision and Marvel could be up after a very long run of years that has seen Activision make Spider-Man and X-Men titles. It should be noted that not all Activision titles based on Marvel properties have been removed and as far as we know video game based on The Amazing Spider-Man 2 (announced last year in development at longtime Spidey devs Beenox) is still scheduled for release this year.
Something is obviously up, but it's too soon to tell exactly what is going on.