+1 for everything Stinger88 said. You'll want to stress graphic design, art, and animation. Having some programming knowledge (which you'd probably pick up anyway) is also incredibly valuable. I'm a UI guy and went toward the coding end. It's really easy to switch industries (if you have to) and finding a job has never…
I forgot to mention a brief background of myself - I am currently a graphic designer at a digital advertising agency. I have been working there for over a year now so I do have graphic design background. I ALSO did go to school and got my degree in Game Art and Design. The only thing I wish they did have a class on was UI…
while this isnt a requirement, i would advise in learning or at least understanding how some code/scripting works as Equanim mentions. There are a lot of technical things a good UI artist needs to master, but by no means need to learn it right off the bat. Knowing and understanding how stuff works will enable you to make…
"I have always loved characters and making games and designing stuff in Photoshop." That does not sound so much like UI to me, are you sure we are talking about the same thing ? There are kind of UI Artists and UI Designers and some that do it all. The UI artists focus on the art execution and the designers on the layout…