I guess I'm divided here. My initial reaction fell right in line with the above statement. We already get spam mail adverts in leaps and bounds, most public sites also have popup or banner adverts ... and I don't even want to think about advert spyware, which I find myself wondering why said companies/individuals who create it aren't penalised.
There are very few places advertising isn't anymore, I don't think I'd want to see the game worlds infiltrated as well. On the other hand we have the concept of game prices/costs of production being positively effected, which may make such a trade-off worthwhile. However, if it isn't done in a creative and discreet way, we may find ourselves wanting for the days prior to said implementation. Somehow though, I doubt that the consumer/gamer will have much of a say in the matter ... unless as a unified group (or vast majority) either in support or against.