Last night at the LDNUG meetup, Bart De Smet gave his presentation on Rx. At the end of the presentation he announced that Rx v2.0 was now officially a release candidate. He then went to go on and release to Nuget in front of the team. You could feel the nerdy excitement in the room.
The release notes can be found on the Rx team blog. The post is huge (~48 printed pages).
Now I have a race to update the Introduction to Rx book to have all the v2 features before they actually release it.