You might be able to claim that Lisp is 90% "homomorphically equivalent", a phrase I don't think I've heard since Mathematics 2, but who gives a shit?

Well, for those who actually have a little intellectual curiosity, the implications are:

    1) Not only can you do anything in langauges X and Y
       that you do in Ruby, you can express it about as 
       concisely
    2) Any libraries in Ruby could be just as beautifully 
       expressed in languages X and Y
    3) There's no reason something that closely resembles
       Ruby but runs *a lot faster* shouldn't exist
    4) Speed is just one factor among many.  There are lots
       of other things Ruby could learn from.  

Sho, there are some who have enormous cognitive dissonance at the thought that their pet language is not the ultimate in the universe. Then there are others that are actually curious about what else is out there, and how the languages they know the most about fit into that continuum. Therein is some valuable and useful information for those who are forward looking.

(For the others, Ruby is awesome, it is the ultimate, there shall be nothing better, yada yada. Now you can rest easy.)

There has been a bajillion hours of awesome work that's gone into Ruby and Rails. There are ways that Ruby and Rails can be changed such that the next bajillion can be several times more awesome. All I'm saying is -- look around and be curious. There's a lot out there to learn!