One big advantage of m4/3 system is its mount, which can use lens from other companies (Nikon, Canon, Pentax, Sigma, etc.). The catch is that you have to manual focus.
EP-1 comes with a LCD. This is the only way to frame, focus, take the shot, and review the results. Because of this low resolution LCD, it is difficult to fine focus, especially when you use fast lens (large aperture) to do protrait.
The minor issue is lack of built-in flash. If you need one, you have to bring an external flash.
If you are P-S type of photographer, it is a cheap and GOOD camera. However, if you are P-S type, why not get a Canon S95 & G12, Panasonic LX5, or Olympus XZ-1?