Tobold makes a good point about the progression of MMO games. I agree that most companies are afraid of themselves and others when dealing with a potential loss of profits. One thing in particular I can give to SoE is that their station account idea is top-notch. I enjoy paying one low monthly fee for several games. (We'll not mention the fact that some of them suck a bit) I think that other gaming companies should adopt that same business model. Instead of trying to beat the numbers or not beat your own numbers why not combine the two and call it a day?
Think of this, if Blizzard does release a Starcraft Online game how many people would swap from one to the other? Realisticly they are not leaving but moving from one to the other. Therefore it will not decrease your numbers but spread them out. What if, instead, you decided to up the monthly fee by $5 and charge $20 for one month of service and allow your players to access both games. That's an additional $50 million dollars for a 10 million player subscriber base. In two years that covers the development cost of the game itself.
No player could pass on a deal like that, especially when (I am estimating here) at least 80% of the WoW players out there have played and enjoyed previous blizzard games. That to me seems like a recipe for success. Though it seems Tobold falls in the other 20% we can forgive him for that. :)