Odds of Getting In
Technical writing is a thriving industry. New scientific and technical products and processes are being developed every day, and they all need documentation of some kind. Also, more and more companies, even those that have never really needed technical writers before, are moving information online. Guess who'll be writing up all of that information? That's right: you.
Now, many other people have caught on to the idea that technical writing is a job of the future, so you'll need to make sure you have the technical background and work experience to set you apart from the pack. The more qualified you are, the more likely you are to find and keep work.