This may come off as condescending, but I think just asking the questions means you are not ready for a new camera. Only you know what limitations your camera has placed on you for what you want to accomplish. If you knew that you would know what camera you need. A new camera isn't going to make you a better photographer.
Comments
What is it about the Canon XSi that you wish to improve?
What types of photography do you do and how will use the new camera? (Please be as specific and complete as possible.)
What lenses and accessories do you have and what do you intend to purchase to meet your photographic needs.
What budget?
Moderator of the Cameras and Accessories forums
An "accurate" reproduction of a scene and a good photograph are often two different things.