Scala Extension Methods Proposal should be adopted, no matter whether Sun’s JVM optimizes temporary objects away, if only for the simpler syntax.

┬áJust because you can do amazing things in libraries like Boost using C++ templates and preprocessor, doesn’t mean the language wouldn’t be better if it could express basic idioms more directly, even at some burden to the language implementer. Pimp My Library is like Boost.Lambda (C++0x will provide a real lambda, albeit without safely handling closure of captured stack variables).