All the merchants that accept bitcoin are not going to wake up and just start taking Litecoin or any other coin. They would probably just watch for a while before making any decision.
Most merchants just don't really worry about something like this as long as it isn't impacting their sales though. Most of them more than likely make large transactions at the end of the week to an exchange and exchange their Bitcoin and pay off whatever they need to, and it would still be cheaper than using other means for them. They don't have to worry about being charged $0.85 because it would be a lot more if they used other mediums like credit cards. They're still happy.