This is why I hate all of those "DRAW MANGA THE COOL WAY!" books because all it does is teach people how to copy someone elses work. The best artists learn from their inspirations but because they practice they end up breaking away from what inspired them and make up their own style. It's people with style who make the most attractive work.
This reminded me of a funny story. I was looking in one of those kinds of books (You know, the kind that has the step-by-step instructions that say "Learn to draw manga!" and all that) that a friend of mine had checked out from the library.. I drew it quickly and virtually perfectly (As I was already a prolific artist). I then tweaked it by adding my own style for two minutes and everyone said it looked loads better than the original. So many of the drawings in those books look like crap to me...
Though I must confess, I have picked up several books from the "how to draw manga" series (Not the AP kind, but the ones translated from Japan). They are a pretty useful resource, though, and they encourage looking at real people most of the time.