Considering that you are possibly biking nearly 90 minutes daily to and from work, 5 days a week, if you enjoy riding your current bike stick with it. When I was searching for my bike for commute, which is approx 45 minutes each direction, I decided that I might as well get something nice, light fast and fun.
Realistically, getting the new bike didn't improve my commute time by anything significant, but I look forward to the rides to and from work... Now if only there wasn't the totally boring 8.5 hr wait in between the To and From!