I think for every study you can find that says that coffee is not healthy you will find another one or two that says it is. For example, I remember reading one recently that found that drinking more then three cups a day improved your 'all cause mortality'.
MMS: Error
Coffee reduces risk of death from some diseases, Harvard study finds - ABC News (Australian Broadcasting Corporation)
Do a google search and you can find lost of things that fall on either side of the line.
Health is a complicated thing. If something is 'healthy' or not is even more of a complicated thing. Water is very healthy but too much and it will kill you.