Depending on your age, your own understanding of your physical capability, and the places you're running, a 6:30 mile is well above average for just about anyone of any age. I've known people to run the mile in the 5min and 4min range, but that requires a much broader amount of training and/or natural endurance. As is the case, and after years of training for track, I can run in the neighborhood of a 6min mile without any training. That said, that doesn't mean I wouldn't be winded as all get out when it was done.

My biggest suggestion is that you not set a goal in stone but instead make it flexible. If you think what you're doing now is easily accomplished, set yourself a goal of 6:00 in the coming months. The biggest thing is to make sure this stays fun and doesn't become a job. That happened to me just after college and I can't get myself to run just yet, but I'm gearing up for it when the weather gets closer to sprinter style.