I carefully went through the lists of features on the Intel store listing for the Euclid. It seems to be primarily focused on robotics, with some Person Tracking (likely for the purposes of avoidance).
I did not see face recognition listed. However, as ROS supports face recognition, I would think the feature is provided that way.
I also did not see a built-in microphone officially listed. However, various preview articles on the internet state that it has a mic and speakers.
As for future .NET support for Euclid, I have no knowledge of that. Given Euclid's robotics specialization though, I suspect it won't happen because the majority of users who would use a Euclid for their project are probably comfortable with ROS and Linux.
If a Windows environment is important to you, I recommend checking out the Intel Joule compute module, which can have a ZR300 camera attached to it. This combination is supported by Windows 10 IoT, the 'Internet of Things' specialized variety of Windows 10. The IoT Core guide to writing apps says:
"C# and VB are both supported as UWP apps and have access to the portion of the .Net Framework available to UWP applications. They support UI apps built with Xaml as well as Background Apps. You can also build Windows Runtime Components that can be used from other supported languages."
in addition to what MartyG wrote:
1) Euclid uses Ubuntu and ROS to develop applcation, ok, are there plans of a .NET framework? My favorite language is Visual C#.
Not at the moment.
2) With Euclid is possible the face recognition?
Euclid is an open system. it comes with an evaluation version of the RealSense person MW which has Person Recognition feature. see here - Intel® RealSense™ for Linux - Person Library: Developer's Guide
3) And the voice recognition (Euclid has a microphone)?
Euclid has 3 microphones built (2 working simultaneous in order to run background noise reduction - not included on Euclid).
hope that help