Oh thank goodness, I assume this means the NDA is over. This thing was in beta for like a year or something.
Anyway, Void is pretty sweet although the selection is limited. You start off with one free game slot which can be upgraded (cool down period between switching games shortened, extra slot for games from the same publisher or share the slot with a buddy's account or just buy another slot entirerly).
As of yet you probably don't need more than one slot active at a time, but it is a great way to try out a whole bunch of Paradox's games (minus the expansions) without a time limit or demo. Most of the other games on there right now aren't very good, but not all. I currently have UFO: Extraterrestrials in one of my slots.
So far it is only available for residents of USA, Canada, Sweden, Norway and Denmark (I don't know if you can change your country in your account to get around this) but they plan on expanding the service considerably.
EDIT: Some notably games available:
Men of War, Kings Bounty: The Legend, Risen, UFO Extraterrestrials, Oddworld: Abe's Oddysee, Elven legacy, Painkiller, Space Rangers, Space Empires IV, Jagged Alliance 2 and others.