Two things:
1. Journalism is a dog-eat-dog industry - it's ridiculously competitive to get into, and ridiculously competitive to stay in. Be prepared to not make too much money, to the extent where you'll need to work another job to survive, potentially. Find a journo and talk to them about it.
2. I've been told by professional journalists that the industry favours people with a particular field of knowledge that isn't just media and communications. Knowledge of history, economics, music, English, philosophy, sociology, science, ANYTHING is going to give you an edge, because it means you have more stuff to play with in your reporting, and in your job applications. Ergo, Arts is a good idea, because it gives you lots of breadth of knowledge (as opposed to say, Biomed).
3. Arts has a lot of real potential careers, you just need to be creative, and often you might need to study further.
EDIT: Whoops, that's three things. I must be an Arts student.