The Twitter debacle prompts this post on project turnarounds by Michael Krigsman at IT Project Failures. Among other things, he advises that project management and communications will be key to ensuring success in the end (but it will be painful along the way).
You don’t have to fix every problem. Get the basic system working and worry about the rest later. I’m sure you’re already thinking this way.
Users will be patient, but only if you make them love you. Everyone wants Twitter fixed, but communication is everything right now.
Learn project management. Wings and prayers won’t work. Bring in experienced managers with excellent judgment who have fought these battles before. You need more than tech folks, even though the problems are deeply technical in nature.
Forrester Research offers this road map for turning around a failed project. I hope you don't have to use it (but you might bookmark it just in case):