Unless I'm working on a project for someone else, I'm more than happy to tell someone what I'm currently writing. Enthusiasiam from readers is great and while I'm not about to give out major plot points, I see no problem with starting any potential word of mouth as early as possible. I think it's also a good way to start gauging interest. If I mention I'm working on my magnum opus about vampire dinosaurs, you can bet I'm going to be checking whether I'm getting "awesome!" or people are looking at me funny and then doing their best to walk away quickly.
