Rx – Open Source
it is a great news for the Rx development community.
Microsoft is still committed to the library’s quality while accepting external contribution into the Rx code base.
Open sourcing is the new Microsoft strategy and you can see other technology that is moving in that direction (for example ASP.NET).
personally I will consider to move Visual Rx into an official Rx code base.
central code base that is being managed by Microsoft is much better than a separate libraries because when a contribution integrate into the code base it is having the Microsoft team quality stamp and developer can easily adopt it with less worries.