Romothecus: IMHO, part of what the article was trying to point out was that WoW is not your typical MMO. That WoW is not growing the MMO market as a whole, because it sort of created a new market, which other MMO's are having difficulty tapping. They will, eventually, but it will be a significant shift for the MMO scene as a whole. I was about to go into a long, fairy-tale like example of flying cars vs. flying horses, and how the horse breeders failed to see that cars are not horses, but it was getting long, and would've angered you anyway, so I'm deleting it. This is, of course, not to say that the industry of flying horses (traditional MMOs) is not analogous to the industry of flying cars (WoWlikes). We might still be able to apply observations from each, but it requires that we stop and recognize that they might not be the same industry, even if they appeal to an overlapping userbase.
Another point I felt worth bringing up is in regards to the accounts vs. people aspect of this discussion. (BTW, lepidus already made a similar response earlier, but you've chosen to ignore the clarification. Let's try again, shall we?) What do I, as a business owner, care for whether its one person with 4 paying accounts, or 4 people with 1 account each? If there are 2 people with the desire to run 4 accounts simultaneously (across multiple MMOs, or in one), the market is 8 accounts, not 2 people. If it were 4 people with 2 each, or 8 people with one each, the market is still 8 accounts, and that's what matters. We don't measure most markets by the number of unique people partaking, we measure them in relevant units. Most of the time, that's $s. Since MMO accounts are nigh-directly convertible to cash, we might use "accounts" when discussing them. On this point, if we say that there are people with 4 potential accounts, and they have 4 of them in WoW, and they decide to keep 3, cancel 1, and go try something else, then we've just added 1 potential account to the open market to be snatched up, either back into WoW, or into another MMO. This aspect of accounts!=people makes your entire rant about calculating how long it will take to go through the entire populations of the various markets moot. If we go back through the whole 5% debate, replacing "people/person/users" with "accounts", and allow that those 5% enter an open market, in which WoW is competing with all of the other MMOs to claim part of the market, then we might account for A. people using multiple MMOs somewhat simultaneously, B. people cancelling WoW accounts only to return after short breaks, and C. a decent portion of the people trying out new MMOs and generally moving around.
Furthermore, in internet time, in the information age, 10 years is a long time. We have access to so much more data about userbases and market penetration than we did in the first 10 years of the film industry, or the first ten years of the television industry. You could argue that we may not know how to interpret that data accurately. But to compare the first 10 years of each of those industries is to ignore their extreme differences as entertainment media. You also argue that WoW has not been around long enough to make educated guesses about their cancellation rates, etc, but at what point in time is Blizzard EVER going to open their books to us and give us an accurate picture of their subscriber base? I see no reason not to make educated guesses based on the information we have at present.
On a side note, I would check your cereal tomorrow morning if I were you. I think someone's been urinating in it. (See what I did there? It's a form of conversational terrorism: questioning your level-headed-ness to bring into question the soundness of your arguments. Nifty, eh?)