MyoSharp
If you haven't checked it out already, my friend Tayfun and I created an open source C# wrapper for Thalmic's Myo. It's hosted on GitHub over here, so you can browse and pull down code whenever you want. We've had some great feedback from users of our API, so we continue to welcome it (both positive and negative!) in order to improve the usability.
Thalmic has plans to release a firmware update to allow more data to be accessible through their API. Right now, MyoSharp is a bit out of date, but once this big firmware update lands we'll take some more time to get it up to date again. Remember, it's open source so you can feel free to contribute!
Troubleshooting
The most common question I receive is "I keep getting an exception about not being able to connect when I run the sample code". I've tried to help a few people through this so I just figured I'd mention it right here for clarity: It's more than likely that your MyoConnect version and the version we packaged with MyoSharp have become out of date. You probably keep your Myo SDK more up to date than MyoSharp is.
Don't worry! So far we've had reasonably good luck just replacing the Myo DLLs in the x86 and x64 folder of the solution. Provided Thalmic didn't break any API compatibility, things should actually just work out of the box. If they DID break backwards compatibility, it's likely not that big of a deal either. You can update the PInvokes used to match the signatures they expect, and again, you should be up and running pretty quickly.
With that said, hold tight! We'll get something updated soon. If you can't wait, then that's my suggestion for how to get up and running. Please don't hesitate to contact Tayfun or myself for troubleshooting. Just post in the comments here and we can try to help out!