1. Massive performance improvements to the pipeline (special thanks to Mattias Nordberg)
2. Integration with JSON.NET
3. Upgrade to Razor v2 engine
4. Visual Studio Intellisense for Razor views
5. Support for Razor layouts, sections, and view-bag
6. Improved Razor view generation performance
7. Compatibility with Mono v2.11+ (including v3)
8. New build process and solution management
9. Continuous Integration builds for MSBuild and Mono, including featue branches and your GitHub pull-requests
10. Lift to OWIN 1.0 specification
11. NuGet improvements for low-friction usage
12. Improved error handling via FIX for IIS
13. Various bug fixes

We still have yet to complete support for Razor partials and HTML helpers but efforts have focused on stability and performance, indeed we believe Simple.Web (in terms of requests per second) is becoming one of the fastest web frameworks available. It's also recognised with the continued popularity of client-side MV* frameworks that server-side view engine generation may no longer be the priority for many consumers, but fast and easy integration with a server-side API is - and thats surely Simple.Web's sweet spot!

If you have any issues or need something, please do raise an issue, we'd love to hear from you :-)