I don't know if I'd ever give up gaming completely, but I've already given it up a lot. I buy less than 10 new games a year, and I pretty much told myself that I'm done buying new consoles except for handhelds.
So once the Wii, PS3 and 360 become obsolete, I'm even more done than I am right now.
Gaming is an expensive hobby, and it's not even my favorite. I love a good game now and then, and I usually spend a few hours a week on it, but it's just not worth as much to me as it was when I was younger.
Of course like other people have said, not much would stop me from simply playing games I already own. So I guess I'll never give it up entirely. I just may eventually stop buying new stuff.