In general animations aren't really that useful in any application if it's used day in day out by an experienced user. They tend to get in the way (at least in my experience). However, that's not to say that you shouldn't build animations into your application.
Animations work best for the occasional user and for demonstrations.
For the former they reinforce that something is happening and, if done right, can draw the attention to the important part of the screen.
For the latter they look good, if done right, when presenting the application in a sales situation. It makes your application look dynamic and in these days of iPods, iPads and smart phones "modern".
To satisfy these two requirements you will need to build in animations, but have an easy way of turning them off.