Online retailers are now taking pre-orders on "Xbox 360 Live Marketplace Points." 1600 points will cost $20 USD, which works out to an exchange rate of 80 points per dollar. Points will be used to purchase items in the Xbox Live Marketplace, including (but certainly not limited to) decals, special rims, and other image-enhancers for your racing cars; clothing for your avatars; additional episodes or levels for a game that you already own, and maybe even special swords and armor for your RPG characters. Heck, you might one day be able to skip that whole "grind" thing and purchase a tricked-out level 60 character in the Xbox 360 version of World of Warcraft (merely rumored at this point, but surely under consideration). Most of these items are expected to cost well under a dollar, which is why they're commonly called "microtransactions."
In short, companies are going to do their best to extract additional money out of gamers. They argue that they're providing fun new ways for gamers to interact with their content, so why shouldn't they charge for that? Gamers might argue that the $50- to $60-dollar price on most games is payment enough. No matter: add-on transactions via the Xbox Live Marketplace will be here in under a month.
On November 22nd, games will move much closer to the "software-as-service" model that the traditional software industry has been advocating for a decade and that MMOG makers have down to a science.