If it takes two years to do something, start sooner.
In an interview with MTV's Multiplayer Blog, Michael Morhaime, CEO of Blizzard, said that they are starting to brainstorm about the next expansion. Wouldn't one think that a smarter way to get expansions rolling faster than once every two years would be to start the next expansion before one ships (i.e. they should have started on expansion three a year ago so we'd only be a year out). In true marketing terms, Michael says they have been putting out an expansion per year..

"Yes, our goal that we’ve talked about is to put out an annual expansion, but we haven’t quite been able to do that. We had one early last year and now we’re sort of late this year, but we do want to decrease the amount of time in between expansions. Although we’ll probably never get it down to a year [between each one] because there’s just so much content. We do want each expansion to be considered a big value for players."

I guess he has a point. Twenty two months can be seen as a year apart in some calendars I guess. Bah, let's not let math get in the way of a good spin. Mr. Morhaime does hit the nail on the head when discussing how well a subscription game is placed for the rough road the economy is rolling down:

"At 15 bucks a month, there really isn’t a better value you can get in entertainment. If you look at other choices that you can make — like going to a movie with a date — you’ve already over your 15 dollars for two hours. I think that players really see that in terms of value for their entertainment, that this the best value that they can find right now. So far we haven’t really noticed a hit from the economy, and we’re optimistic that we’ll continue going strong, especially with the launch of “Wrath of the Lich King.”

Preaching to the choir. I love my subscription games, it keeps me from spending hundreds per month on single player one-night stands. There are a few more tidbits of information if you have a few minutes to check out the interview at MTV's Multiplayer Blog between playing your main and your Death Knight.
In case you missed the launch events, watch our video interview with M. Morhaime at the Lich King launch last week. And for the latest guides and information, make sure you go to our Wrath of the Lich King Portal.