If you want to do Law @ Deakin and you're unsure of whether Law is truly right for you, I recommend you do a double degree (Arts/Law, Com/Law, etc). The ENTERs at Deakin would be low enough for you to get into a double degree and, if you do decide that law isn't right for you, I'm sure it would be a much simpler process to revert to a single degree using your alternative from the double degree than it would be to switch single degrees entirely *hopes that makes sense*. You'd also get plenty of credit and wouldn't have to start over again.
Also, employers in the legal profession will look highly upon people with expertise in a second area so if you liked both degrees you could keep going with both (You could really use an Arts psychology major or knowledge of business or commerce to push your career forward, depending on where you'd like to go).
The third alternative would be that you find that you absolutely love law to no end and you hate your second degree, so you drop the Commerce or Arts or Science (etc) side of your double degree further down the track. It's really about giving yourself more options I spose, but that's just something to think about. If I was unsure, that's what I'd do.
Deakin Burwood '07 Clearly-In:
Law 93.65, Arts / Law 94.00, Commerce / Law 94.30, International Studies / Law 94.05, Science/Law 93.95.
There were some more double degrees with Law in them, but they're only offered @ Geelong campuses.