Does it make a difference when authors step into another's shoes?

Guest blogger Jason Sanford often rants on his website at www.jasonsanford.com. His fiction has been published in Interzone, Year's Best SF 14, Analog, Intergalactic Medicine Show, Pindeldyboz, and other places, and has won the 2008 Interzone Readers' Poll and a Minnesota State Arts Board Fellowship.

So a month back I wrote a snitty little post on why I wouldn't read And Another Thing... by Eoin Colfer, which is the newly authorized sequel to Douglas Adam's Hitchhiker's Guide to the Galaxy. I mean, dammit, I love Adam's trilogy. I think the first three books are as near to perfect as fiction writing can be.Then Colleen Lindsay offered to send me a copy of the book to read. When the book arrived yesterday, I opened it and read a bit and found myself laughing. Which is deeply disturbing. I mean, if I like the book does that mean individual authors and their particular creative visions no longer matter for crap?Okay, maybe that's a bit melodramatic. And I must finish reading Colfer's book before I can say if it is good or not. But this has made me wonder. Are we entering a world where fanfic—i.e., diving into the imaginary worlds of others—is the new norm among writers?When Charles Schulz died, no new Peanuts strips were created per his family's request. But this fact gathered so much attention precisely because it was so unusual. In the comic book and movie worlds, it is common for multiple writers, directors and illustrators to work on properties like Spiderman over the years. This results in storylines which never truly end; in characters which never truly develop and change. When a particular take on a character or story grows old, you simply reboot it, as was done to the Star Trek series with the most recent movie.Perhaps this is where all fiction is headed. But one of the reason's I read fiction is to experience another person's vision of the world. My fear is that this interchangeable cookie-cutter view of authorship will result in stories lacking the vision which first drew us to them.Any thoughts from other people?