If you need raw performance you should look to another language because I don't think that will ever be too high a priority for Ruby.
I reject this philosophy: Lua is also a highly expressive programming language, and LuaJIT runs 75 to 100 times faster than Ruby 1.8. There's no reason why the Ruby community should settle for lousy performance.
I'm trying to track down a bug in the Rubinius JIT as I speak. Rubinius may be faster than 1.9, but I can still see dozens of really obvious optimization opportunities. If nobody screws up method caching, Ruby will eventually be 10 times faster than it is today.