Im gonna do mechatronic (hopefully as well). There is a fair difference between them. Mechatronics is basically robotics... intelligent mechanical systems. It's an integration of mechanical and electronics and I know you can branch off in to the automotive industry, biomedical (ie artificial hearts)... basically any machinery that works on computerized systems (ie. ABS brakes)...
With mechanical it has far less to do with electronics and is basically the mechanical systems that arent run on computers and think for themselves. The mechanical part though is essentially the same.
Btw, definately go to UTS.
Best university for engineering. Plus they are the only uni that offer you two 6 month internships where you can work in the field anywhere in the world... i was talking to a guy who did his in America in a car factory! UTS is definately the way to go. and there the degree is called 'mechanical and mechatronic' and thats what ill be doing... if they let me in