IMHO, bitcoin will follow linux in this regard. Think, e.g., Redhat. Their main source of revenue/profit is support through the sale of a reliable/predictable distro that they harden for business. They, in turn, give back most of their work to the community (as they must per GPL).
Someone like that will develop and package a hardened turnkey solution and related support infrastructure for merchants that makes it dead easy to accept bitcoin without having to worry about its volatility.
I'm sure folks have to be working on this, if they've not already released something, but am too lazy to google before that first cup of coffee.