This article appeared in my inbox today. Keeping in mind that it is written by implementation consultants, so they have a vested interest in having people believe they are needed, it is still a very good 10 points to consider.
Of course, keeping in mind that I also am an implementation consultant and have a vested interest in guiding companies through their implementations.
Here is the article. You can get away with just reading the 10 points in big blue letters