Joshua Porter wrote his seven reasons why he thinks web apps projects fail (not just) these bubble2.0 days.
It is very interesting reading, so hurry up, click click on the link, read it and learn!
His blog post: 7 Reasons Why Web Apps Fail
And as a bonus here's one link, Jim sent me about Characterizing People as Non-Linear, First-Order Components in Software Development.
After those years in web business, I must only agree with the text. People are actually the main reason that causes projects to succeed or fail.
UPDATE: Joshua posted 7 More Reasons Why Web Apps Fail.