The only shocking thing is that Drosnin has written three of these books.
It is basically just playing with numbers and letters in a random book to cook sentences that sound meaningful. You don't need the Bible at all to achieve this. You can take the method Drosnin used and apply it to any book and get results that sound meaningful. Instead of the Bible, you can use The Lord of the Rings and get the same kind of "predictions".
This is from Skepdic:
http://www.skepdic.com/bibcode.html
Drosnin once said, "When my critics find a message about the assassination of a prime minister encrypted in Moby-Dick, I'll believe them." McKay promptly produced an ELS analysis of Moby-Dick predicting not only Indira Ghandi's assassination, but the assassinations of Martin Luther King, John F. Kennedy, Abraham Lincoln, and Yitzhak Rabin, as well as the death of Diana, Princess of Wales. Mathematician David Thomas did an ELS on Genesis and found the words "code" and "bogus" close together not once but 60 times. What are the odds of that happening? Thomas also did an ELS analysis on Drosnin's Bible Code II: The Countdown (2002) and found the message "The Bible Code is a silly, dumb, fake, false, evil, nasty, dismal fraud and snake-oil hoax."* Does this mean that God put in a code to reveal that there is no code?
Here's the CSI page about the first Bible Code book by Drosnin, describing the method he uses:
http://www.csicop.org/si/show/hidden_messages_and_the_bible_code/
Quote:
The promoters of hidden-message claims say, “How could such amazing coincidences be the product of random chance?” I think the real question should be, “How could such coincidences not be the inevitable product of a huge sequence of trials on a large, essentially random database?”