Merchants are not speculators, if you price something in bitcoin and you hold bitcoin at the end the day you may have less value than you should, or you can have more and you have to pay capital gains and it complicates your accounting when the only thing you want to do is to sell oranges...
Not really, the ultimate dream is to have Bitcoin completely unpegged from any other currencies, and people using it directly to buy and get paid, that's how the Bitcoine conomy would fully flourish. Of course, as long as governments exist which issue their own currencies, this is just a fantasy.