The Sims 2 will be huge for the market it caters to. Most people I know rarely play their game...they just like to landscape, build houses and decorate them.

That's been my experience, too. People who don't know about Poser, or don't have the time or patience to learn it, use The Sims instead. If you look around the net, some people have put up elaborate "graphic novels," running hundreds of pages, using Sims screenshots. Sometimes, the characters are TV or movie characters, so it becomes a sort of illustrated fanfic.

I think there is some overlap with Poser here. (Not all Poser users, of course, just some.) And there could be huge bucks in it, because the market for Sims stuff is humongous compared to the market for Poser.

Then there are games like The Movies:

http://www.themoviesgame.com/

It's sort of like The Sims, only you can direct the action and make your own movies. I suspect this is what many Sims and Poser users really want to do.