I hate to focus on the negative but Smashing Magazine has an article dedicated to the 10 most common mistakes made by people when choosing a logo, most notably relying on current logo trends and also relying on color for your logo. Everytime I personally design a logo I always work in black and white because, I was taught that if a logo works in black and white, it’ll work in color.
Also many people seem to follow trends such as the current ‘mac’ trend where they want to refelct everything they see, or put a shine on it, but 5 years from now you’ll need a new logo because there are always new trends. You want your business identity to stay with you for a very long time, look at Coca-Cola, they don’t change their brand very much.