Xbox Live is in the unique situation of being able to sell ads to the end-user, sell the ability to access end-users (via Marketplace) to publishers/developers, and take a cut of those purchases between publisher and end-user.
The article discusses this as a problem, but as far as Microsoft is concerned, it's everything as it should be. Customers aren't pissed enough to leave because they still see value in the service they're paying for and the ads are pretty unobtrusive. Until end-users or publishers get annoyed enough at the status quo to make a significant enough dent in their profits, Microsoft is not going to care. As it stands, we'll pretty much have to wait for one of the big name publishers to get annoyed enough that their games aren't getting the exposure they want, because the current minority voice of end-users annoyed at ads just isn't loud enough, and I don't think it ever will be. Publishers and their triple-A titles on the other hand have a ton of sway.
Of course, it will be interesting to see if the increasing dependence on Microsoft continues. If so, it might get to the point where the publishers don't have much sway as far as negotiations are concerned. Given that the gaming industry (excepting a few smart companies and indie devs) are basically abandoning the PC market in favor of locked-in console gamers, we're near the point where the console manufacturers and their signing keys are going to be the barrier between publishers and their continued success (or eventual failure).