Arc already is a possible production language. Look at C. It is one of (if not the) most popular language... ever. A massive amount of code has been written in C. C is used to write the OS that you are using right now. C++ (which is similar to C) is used in most web browsers.
Yet, I would hardly call C or C++ very good "production languages", at least according to my definition. A smart hacker with a bad language is probably far more productive than a bad programmer with a good language[1]. Languages can help or hinder, but ultimately it comes down to the programmer.
So, yes, you can use Arc for production work. It may not be designed for it, but it is still possible. It also helps that you can use Racket code alongside Arc code, letting you tap into Racket's power when you need it. If you want a language specifically designed for production work, then Arc is probably not what you're looking for.
But if you want a nice lightweight language that is designed to be very hackable, malleable, and concise, while still giving you the underlying power of Racket when needed, then Arc could very well be what you want.
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* [1]: Of course, a good hacker will probably despise programming in a bad language, but I still think they would be more productive than a bad programmer using a good language.
