From a business perspective, big shots will probably want the price to have even a hint of stability before adding it as a routine payment option.
True and that is already starting to happen. There have been days where the price stayed between 19 and 20$/btc. Very easy to accept btc at that point.
imo a couple of days is not good enough, try several months or even years of price stability and THEN we will be talking
That kind of stability is a ways off. At the start of 2013 there will still only be some 10,500,000 bitcoins in existence. Of course, I'm making the assumption that bitcoin is still around and people want them.