In his e-newsletter, Tom Peters! Times, the management guru (www.tompeters.com) suggests several ways to get re-excited about a project when you've gone a bit cool on it. Here's one I thought was especially good:
"Sell: The easiest way to get excited about a project is to sell it to someone else. That forces us to think about what is important about the project, and why the project matters. Sit down and develop a compelling 3-minute pitch that highlights the benefits of the project and why you are in love with it. If you can't get excited about your own project, neither will anyone else! Practice the pitch with a friend. Once you feel comfortable with it, share the pitch with someone who understands nothing about the project. This will allow you to determine how clear your pitch is. Lastly, refine your pitch, print it out (in color), and put it in a visible place to remind you of why this project matters."
In scriptwriting or book writing, we are used to pitching something at the start of a project, to get a commission. But it's very common to have the "second act blahs" (the second act being that big chunk in the middle), and re-pitching the project, even if only to yourself, could be a great way to get back your enthusiasm.