I haven't read any replies, so sorry if this is repeat information. I just recently began weaning off of coffee and all caffeine. I found a lot of informataion about the dangers of it (regardless of how many doctors say its safe, I really don't care) and made a choice to give it up. Caffeine produces a "fight or flight" response in your body as often as you take it, so in a sense your body is in emergency mode all the time, horrible for your heart. More infor here...
Caffeine Effects: Kicking the Caffeine Habit