Quick article about the effects of coffee. I myself don't think that coffee is bad for you, yes if you drink 2 pots a day there will be some negative effects. Like everything else moderation is the key.
I am currently not drinking much coffee right now, primarily because the gels that I use when I race have caffeine in them 50mg (equal to 1/2 cup of coffee) and if you lay off the coffee for a month or two prior to the race you will feel the effects of the gels more. After this Sunday though I'll be back on the bean.