I stumbled across a link to some WOW publish notes. It appears that Blizzard is now pushing out fixes virtually every day. And it isn't just one or two critical things needing fixing, it can be a dozen of fixes. They must feel very confident about their publishing process to be able to do it every day. Well with a game that has 12 million people playing, I guess you need to ramp up publishing to that speed.
On the subject of Blizzard, it appears they are over the "we have how many subscribers?" shock and are getting down to business. They were making so much profit per year but were not working on anything. Now they have Starcraft II, Diablo III and a secret MMO project all in the works. Plus with all that money coming in they have an unlimited amount of time to polish their games. These titles will probably be the most refined in the history of video games. Starcraft II likely would have been released up to a year or more ago from a publisher such as EA who likes to rush things out the door (Warhammer Online). As long as World of Warcraft keeps going, in four or five years Blizzard could be a one studio game producing powerhouse. Their no longer restricted in terms of time and money with a gravy train such as WOW under their belt. But who knows how long that will last.
Plus what is up with taking 18 months for an expansion? They should be able to knock that down to a yearly release. As time goes on players are going to get more and more bored. With no news on an expansion yet it doesn't sound like they'll have one ready. Who knows, maybe it will be a big surprise.