I'm sure that if other publishers notice that Activision raised the price of their games and are still selling, most of them will do the same. Yes, that means EA too.
It's hard business. We, as gamers and buyers can rage all we want and talk about boycotting as much as we like, in the end, it won't make a difference. If they manage to pull it off, well, good game to them. They'll do exactly that what many other branches have done before them.
No, you can't compare this to the movie industry where they get the most money from theatre ticket sale and every dvd that they sell afterwards is a nice bonus. This isn't a flatscreen tv production industry where components can be produced for less money due to evolving technology and can therefor be sold for less money.
The gaming industry has become about money. Lots of money. It's no longer a couple of geeks programming a game in their basement during their free time. These are companies with employees, licenses, equipment and whatever not, that all need to be funded. Those won't come cheaper. They have to cough up money for it, and we'll make sure they get it back, with a little extra on top. That's just business. Yup, it sucks for us, but c'est la vie.
Sure, let's hope, for our sake and that of our wallet that they won't, obviously. But what if? You can buy less games and pretend you're boycotting. But are you going to quit gaming altogether? Are you now going to pirate everything to prove a point? I'm pretty sure that people who will pirate, are the ones that are already pirating. Is it going to change the gaming inductry? Will gaming as an average man's hobby die? I think not.