Incidentally, there's already several funny parody videos involving the "I'm Linux" guy that have been circulating for a good while now. YouTube it!

Python makes sense to a degree, but its trademark The Whitespace Thing might prove especially frustrating, as adolescents tend to pay little attention to subtlety, so I could imagine the somewhat-subtlety of indentation could be problematic. Maybe I'm wrong; this is untested.

In general, I like the idea of using a clean, interpreted language like python. If a compiled language is used, the interface used should make that automatic. Still, playing with an interactive session might be invaluable.

I guess that doesn't really conclude anything.

Hmm. All three of those work fine in Python. The meaning of x, y, and z would affect how I stored my variables, but I would probably use something like your first option (though I would probably add spaces around the operator). I would also use something like that in C and maybe even PHP. I would only use your most pythonic solution if x, y, and z should be thought of together in some way. If really wanted to save space, I would go with the top solution of x, y, and z don't relate in some way.

Shorter does not mean better. x,y,z = 1,2,3 does not make source code clearer, as you defend meaningful whitespace as doing.