The article above is an interesting one, since Strauss Zelnic, chairman of Take-Two, clearly states the decision to delay Bioshock 2 was to make "...a more compelling consumer experience and a better performing product in the marketplace."
The question is whether the quality of the game or the quantity of sales is more important to Zelnic - and we won't know that until 2010. If a delayed game turns out to be a memorable one, people shut up about the delays in a hurry (see almost every Valve or Blizzard release). Part of me still thinks that Bioshock doesn't need a sequel, and while I've been avoiding previews for it, what little I've read indicates that 2K genuinely wants to improve on the first game.
But even if it is merely a finical decision, I can't entirely knock Take-Two for it. The original Bioshock came out in late August, at the end of the traditional summer time lull for games. A lot of gamers probably found Bioshock because there was nothing else new out there. How well would it have performed in the fall of 2007, up against The Orange Box, Mass Effect, Assassin's Creed, and, most importantly, Call of Duty 4?
Of course, Bioshock is an established I.P. now, so releasing the game during a lull makes less sense than it did in 2007. On the other hand, it's not an established multiplayer I.P., and a release in November would have put it up against Left 4 Dead 2 and Call of Duty: Modern Warfare 2, strong multiplayer titles.
One thing's for certain: I can't wait till 2010.