of course it's not about "near future" since no real competition is up yet, i said it in my first post too. And lead designer is pretty big, it's not "just" a designer. since they already discussed this possibility and thought it might be necessary to make it free to play, it pretty much proves what i said that even though the winnings are pretty big right now, they know it wont be forever and plan ahead, as they always have, investing in their other franchises and expanding their fanbase to keep the money flowing. in a recent interview Kotick himself mentioned that Starcraft II helped increase their income this year and even supported such releases for the future.
PS. use edit when you have to add something, i'm getting tired of merging ur posts.
also, the profits of WoW may be high but there are already plans from Blizzard to make it free to play if serious competition happens to be released (i'm guessing they're mostly thinking of Star Wars: The Old Republic).
Starcraft II really skyrocketed Activision-Blizzard's profit this quarter and they definitely plan to have more single-player titles to get more fans interested. Especially the Blizzard franchises being united through the new battle.net will keep people both in WoW and the other games too.