Nikon 4500 vs. Canon G2
I was deciding between these two models as well and went with the Canon. I had owned a Nikon 990 that was stolen. I needed to replace it with a user friendly set up that had a TTL metering for a flash. Nikon currently does not offer that as far as I know. They do have cameras with a hot shoe, but you have to manually adjust the exposure.
The 990 had a terrible flash. It had spectacular macro capabilities which I enjoyed personally, but since the camera was primarily for our business use, I had to get something that would handle those requirements, which were the metering, ease of use, and wide-angle capability.
I ordered the camera through our insurance so I went off of reviews only. I was very disappointed to find that the wide-angle adaptor lens is just about useless. The barrel distortion is unbelievable. I am amazed that they would even put a product that bad on the market. They would have been better off to not even offer it.
If I could disregard that, I would probably really like the camera. While the macro capability isn't up to the Nikon standards, it is adequate and the flash is better and the camera is easier to use. The overall package is smaller due to the fact that the camera has a hot-shoe and it eliminates the need for the flash bracket.
If you can live without the wide-angle adaptor, you will probably be very happy with the Canon. The software that comes with it is also very nice.