I guess in terms of business, Blizzard could be constituted as Activision's 'bitch', but having an executive who went to a business school be in a top marketing position over a guy with a CS degree who's good at actually making the product isn't that bad. I imagine the guys in the development offices still get to do their thing, since their thing has proven to be the best business model, and Activision would have to be foolish to interfere when Blizzard is only behind Maxis for highest grossing (and probably net) revenues from a single game developer.
EDIT: In North America, at least, I think Nintendo is managing to nudge Blizzard down to third with the WiiFit, while The Sims is still at the top of the most sold list, last I checked on Wikipedia. Since there is hardware on the WiiFit, though, my uneducated guess would be that they gross more (clearly, since it's uber-expensive) but also have a higher operating cost. Then again, maybe Blizzard grosses more because a full package costs about $80 + (n*10), where 'n' is the number of months the person buys a subscription fee, assuming that the game and all three of the expansions (including the upcoming one) are purchased and all four boxes cost $20. So for people like my Dad who have been playing since 2003 or 2004, they can probably gross upwards of $300 per customer. I don't know how much their operating costs are, though, so I can't make any speculation on how much of that they actually keep, or how much is actually distributed to their executives and stock holders (wage and salaries of all the people working on Blizzard games, including the leads, is already factored into the operating costs).