Rx 2.0 is RTW! Get it here. I caught up with Bart at his whiteboard (of course) to discuss the significance of this release as well address some of the great additions to Rx as outlined below (many of the topics below have been discussed in depth in other Rx interviews with Bart.) We also talk about the new experimental build shipping model. Much of the time is spent talking about the portable libraries architecture for Rx for Windows 8, .NET 4.5, WP7/7.5 and beyond. Bart has been very, very busy and as usual his engineering is golden.Tune in! It's always a pleasure to geek out with Bart. So much to learn. Congratulations to the Rx team!!! The highlights of Rx 2.0 include: Support for building Windows Store apps for Windows 8. This includes primitives to synchronize with the Windows XAML CoreDispatcher and interop with WinRT events and IAsync* objects. Support for Portable Class Library projects, allowing code reuse across ".NET Framework 4.5" and ".NET Framework 4.5 for Windows Store apps" projects. We're planning on adding Windows Phone 8 support to this going forward. Integration with the new C# 5.0 and VB 11 "async" and "await" features. In Rx v2.0, you can await an observable sequence, allowing one to apply the power of Rx to the new asynchronous programming model. Enormous performance improvements, with a 4x speedup of the query pipeline, vastly reduced object allocation rates, massively increased throughput of schedulers, and much more. An improved error handling strategy, enabling higher resiliency and proper resource cleanup for queries in the face of user errors at various levels. Thorough revisit of the way we deal with time, to improve efficiency and predictability. This includes better support for periodic timers, improvements to absolute time scheduling, etc. Various new and improved query operators.