Defining commands and their corresponding actions is something I think an open source could actually do much more effectively than companies. When everyone in the world can contribute commands rather than a single team of software devs it is possible build up a much larger collection of them. I would really like the ability to add commands to a natural language command system when a command I use doesn't work. Also, I think that a reprogramable command system would open up an interesting programming paradigm where one could define new commands and actions in terms of other commands in the system. For example,

What's new?

> Unrecognized command

When I say "What's new" read the "In the news..." section of Wikipedia's main page.

> Acknowledged.