As gaming becomes more mainstream with the consoles growing in popularity, the marketing model will probably revert back to what it's always been. Gaming is transforming from what it was two or three years ago into a mass produced media product like movies or television. Sports games are the prime example of how this works. Same game, few new features, updated rosters for the upcoming season. Viola! $50 game ready to go.
The PC gaming crowd is more like you describe it Baker, but we're losing the edge in the marketplace. We're becoming a niche market for publishers to toss a bone every now and then. While this year has been very strong for PC games, the number of titles put out has dwindled. Shelf space at retailers is almost non-existant... Go check out a GameStop, I challenge you to find the PC shelf... it took me 10min to find it at the one near me, it was one 2' shelf with about 10 boxes on it. That was it. The freaking action figures got more shelf space than PC games.
I still think though that gamers as a whole, PC or console, clamor for the next installment in their favorite series more than they want truely new games. We love Baldur's Gate, Halo, Master of Orion, Final Fantasy etc... We know the quality to expect from those titles, and once we've finished the latest version, if they were good enough, we want more more more. We want new stories, in a few years we want improved visuals, fewer bugs etc. I think that still trumps the desire for original titles.