This is a pretty awesome project by Mozilla Labs. I’m really liking it! - great potential for scalability into whatever it is that the end-user wants to do with it.
These technologies make you think about how you were living without them. So naturally efficient.
and that my friend is the essence of a killer app. Although, I wouldn't classify Ubioquity as such right at this point, but it has the potential to become one. For techies and pseudo-techies, I can see this already affecting the way they surf the web... for the mainstream though, the options available for various online artifacts and their associated commands need to be a little more seamless.
Lafanter, it's not a language per say - end-users can define the commands in a way they deem intuitive to themselves. This is by far one of the best examples of a user-activated and user-generated mashup.
This sorta reminds me of the "/" from the DOS based Lotus 123 days, where you press / and then all the other commands to do anything. Dunno where that thought came from :)