Always on DRM is also a threat to the preservation of artistic works for future generations. Folks still play the early Civilization and Sim City titles even after all these years.
All server-based MMOs will be canceled sooner or later. Dead sites will be preserved by the Internet Archive, but dead MMOs will be known for future generations only in Let's plays and secondary sources. Relevant article, "MMO graveyard": http://mmohuts.com/editorials/mmo-graveyard
Which, interestingly, is why one of the head developers who worked on Warhammer: Age of Reckoning (the MMO, that was quite enjoyable) wants the debug dev version cleaned up and release: It removed all the online content, and just let you take a character through the entire world, all offline. He wants to do that, as a way of preserving the world. It might not have the content, but its something, and an interesting take on it!
