Odds of Getting In
As industry barrels along and more buildings go up, more fires are started. Therefore, firefighting is a growing industry. However, as dangerous as it is, there are a lot of people going after these jobs (see "Glory"). Expect quite a bit of competition.
While you can't exactly emerge from college with a PhD in firefighting, there are certain things that can set you apart and make you more eligible than others for a sweet firefighter position. If you're in fantastic physical condition, have a dedicated work ethic, enthusiastically engage in training exercises and drills, and can demonstrate an attitude of fearlessness (not to be confused with brazenness), you'll be on the short list of viable candidates.
It can't hurt if you have a pet Dalmatian, either. Every firehouse needs one.