Are you actually experiencing a problem now, or just anticipating one? I currently program primarily in Ruby which is one of the slower languages around, and I've yet to max out a CPU with a web app, and I simply wouldn't use Ruby for serious number crunching.
Maybe my view is a naive one, but I feel that if Arc is successful, the effort to improve performance will be made.
On the other hand, it is a bit strange to see the docstring repeated like that.
Well, that's actually what kept me from Ruby and made me stick with Python for a while. I needed a little speed. Not that much, but Ruby was just below the barrier.
