I wonder if you read through the archives regarding long term use of nicorette? I personally know a few who have been chewing and are addicted to it. One has been chewing now for 12 years and suffered his second heart attack : ( His doctor is convinced it's because of his prolonged nicotine intake, even though its through the gum.
Here is a link to someone elses candid talk about long term use:
http://www.medhelp.org/posts/Smoking-Addiction/Effects-of-Long-Term-Nicorette-Use/show/730769
Also, google it and you will see what others have to say about it.
I used the commit lozenge for a brief time and when my dentist saw what it did to the inside of my mouth, he said that I should stop it immediately. I think that commit and nicorette have basically the same ingredients.
I'm happy that you gave up the smokes, but maybe you will consider giving up the gum now? We will be here for you : )