Having dealt with this exact same issue (played out in a very different way) just this past week in blog land, I hope that THIS isn't true (although, it completely appears that it is). If it is, I am, once again, disgusted that people could do this type of thing.
My wife is dealing with cancer (along with several other very real, and very life-threatening health issues). Stories like Michael Guglielmucci (author of the song "Healer") are amazing, which is why, if it turns out to all be a lie, they're incredibly detrimental.
I first heard of his song "Healer" probably 6 months ago while my wife and daughter were both in the hospital. Several people sent me links to the lyrics and/or recording, thinking that I would find something special about it. I admit, it's a good song, but, for whatever reason, I never really gave it much notice. Maybe it's just my personality, or maybe it was God trying to protect me from even greater disappointment. Either way, I'm thankful that, other than being frustrated at what this guy has done in the Christian and Cancer communities, I have no real personal investment in this.
Unfortunately, thousands of believers do (have a personal investment), and I pray that Michael's confession of his lies will not cause those who found great comfort and strength through his song to doubt God or those of us who are affected by cancer...