The keyboard looks unusable. Even in her demo there were several mistakes. Handwriting recognition one letter at a time is slow, tedious, and error prone. An on screen keyboard would be better.
The mouse functionality looks interesting though. I want to see how precise it is. Maybe use the button to adjust sensitivity.
As others have said, it doesn't seem very ergonomic. By moving the ring to the tip the index finger would work but at that point I might as well have a Joy-con.
I think it's cool and needs more prototyping. A smaller size would be the next logical step.
Would be interesting to be paired up with something like Google Glass or Apple Vision. That way you can control something without having having to lift your hand like you're trying to use your Jedi powers to convince someone that these aren't the droids they are looking for.