While I think it's likely that at a lower price and with the list of games growing PS3 will start going better and eventually sell more than 100million (but not before the last months of 2013 if Sony guesses all the right moves, most likely towards the end of 2014 if like natural it guesses most good moves but not each one), I'm persuaded Wii will sell more and has a very good chance to exceed PS2 sales, if it stays on the market long enough, it all depends on Nintendo plans on its life and how and when to launch Wii2 and if it has to coexist with Wii1, I think nothing else could stop it.
It's very simple: Sony can save PS3 doing the right moves, but Nintendo with Wii did almost always the best moves since the beginning.