I saw asetniop last week, so I dug an old concept for a chorded 10 finger input method out and implemented it in Elm. Switch your system layout to US and try to type something using the chart.
The next phase will be me learning the layout, so I can see if this approach is even fast enough. :-)
Update: the layout will remain as it is right now - at least on the basic layer. The input method changed: you now don't have to leave all keys to register a chord. Instead you have a 60 milliseconds time frame to press a chord. To speed this up, change hands or leave all keys. 60 milliseconds seem rather short to precisely hit a chord, but it should be enough after some training. Try it out! The big bonus with this system is that —if two consecutive characters are on the same hand— you can switch from one chord to another without leaving all keys. Also, special characters got added.
Finally a keyboard for emacs users! But yeah, this is a nice demo. I managed to type 'www.facebook.com' in around 30 seconds. I would be curious to see if it can approach faster typing speeds after some learning and familiarisation. My gut feeling is that it won't because having to take all your fingers off the keys between letters. It might be faster if a chord is registered after a group of keys have been pressed but before they have been released.
Still, an interesting idea.