Bart De Smet has been very busy. As you can imagine, the latest release of Rx (v1.11011.11 (Experimental)) supports the latest (developer preview) .NET version, 4.5. In this release, Bart and company have forged a deeper synergy with the async/await Task-based asynchrony model (see Prefer Async Policy in the Release Notes for this release for more info and watch/listen to this conversation!). In addition, Rx can be used in "Windows 8" Metro style apps.
Rx v1.11011.11 (Experimental) features include:
Improved Exception Management
Prefer Async Policy
Interoperability with Task<T>
FromEventPattern Support for WinRT Events Various Changes to System.Reactive The New
This release of Rx includes support for WinRT interop and to build Metro style applications leveraging Rx for event processing