Heshiming is pretty dead on here. I find that art is the practice of hiding your sources of inspiration and design is the practice of clearly representing them. Video games are unique in that they sit in the middle of practical design and construction meeting many different mediums of art, all made digital for ease of presentation. We have to have UI and control systems that people recognize the same way a car engineer has to add a steering wheel instead of a joystick while designing art that could be just as easily viewed in a posh Paris gallery(creative) as it could in a New York coffee shop(accessible). To boot it has to be animated to meet the standards of today's audiences (thanks a heap for setting that bar Pixar) telling stories that mean something.

To make something "new" should be done...carefully.

I think the trick is to find experiences that tickle you and bring them to games you already love. For many of us this will mean combining games, but I think the more designers explore physical/social/cultural experiences and combine them with game designs the better game's will get.