An interesting post by Teclisen in the Fires of Heaven forums about the "real story" behind Vanguard: Saga of Heroes. Within the MMO community, Vanguard had a significant following, and hopes were high that Brad McQuaid could repeat the success he had with EverQuest. Launched in January of 2007, it did not meet expectations.
But Teclisen has a more interesting story than stability and performance issues, if he is to be credited.
Behind the scenes organizational issues have, more often than not, been the reality behind game delays that I know of. A AAA-title is a weird beast, a creation of dozens of people working in concert on something that often lacks objective measurement for success: "Is it fun? Is it pretty? Is it original?" govern a great deal of the success or failure of most projects, and with large teams hanging on the success of even the least experienced intern, it is a wonder that games succeed at all.
I don't know Teclisen, and don't know anyone at Sigil personally, so I cannot say whether the story as told is accurate. I have seen, however, similar episodes of disorganization, competence and lack thereof, and heavy burdens being placed on inexperienced developers. And I've shipped my fair share of truly awful games, and know first-hand that the developers behind them are often excellent, but organizational, financial, or scheduling constraints outside of their control often have a much greater impact on the final result than we wish would be the case.