The only way a merchant would want BTC is if a supplier wanted BTC. This could be just somebody selling a service, which would be fine, but if you are buying an actual product, you'd need the manufacturer to want BTC, which would mean you'd need some of the people working for the manufacturer to want BTC (or I suppose the raw goods provider).
What I'm trying to say is that no big company is going to want BTC at this point unless they are either (A) created from the ground up around BTC or (B) they have some way of offloading that BTC to individuals that want BTC. Companies at this point wont want BTC, people will.
Companies don't have to want BTC at this stage. Let them take their fiat.
But when they start seeing the option to pay their suppliers in BTC they might look further. It is only AFTER mass adoption that most merchants will want to accept it directly. They don't want to be speculators, but if it can cut costs they might consider holding some briefly. PayPal could give Bitcoin quite a bit of momentum in that direction by accepting Bitcoin payments for conversion to the recipient's local fiat for all accounts. They already have the legal team with the most expertise in internet payment and currency conversion regulations. They could leverage their unique capabilities, but they also know that they can time their entry because any other entrant has to spend a lot more time and money deciphering and meeting regulations. Just because they will be ready to throw the switch doesn't mean they will just yet.
