I left my camera unused for two years, with the battery in it. I've got it currently plugged into my computer to charge, and nothing is happening. Is it likely that the camera itself isn't working or is it more likely the replaceable battery?
I've got a Canon 20D that I've kept around to use as a training tool for friends and family looking to try out photography (it combined with a nifty fifty is only ~$200 worth of kit that I don't really care about). Point is, it has gone and still goes a few years between stretches of use. It works fine.
I realize this is anecdotal - but 2 years is really not that long. As long as the camera has been kept dry in that time, the battery will just need a charge. As has been suggested, use a wall charger or look into a replacement battery. If you plan on storing electronics for any length of time, try to remove the batteries beforehand.
By far the weakest link in your problem is the battery. LiOn batteries will die after 3-5 years, and leaving them unused could reduce their life.
Take the camera to a camera shop and see if they have a battery for you to test. More than likely, you problem is due to a dead battery and not something internal in your camera.