I have read Shiver and love it! I should mention that I am a huge fan of Twilight, and in fact this entire genre. Yes, they are both Young Adult Urban Fantasy books, and both authors have taken artistic liberties with their 'supernatural' characters BUT I don't really think they should be compared beyond that. I am pleased that SHIVER is moving to the big screen, I hope that it will be blessed with a great screen writer and director who will bring the book to life, not re-invent it.
btw 'latching onto Twilight's success' sounds kind of negative... I think bringing the world of Young Adult books to the bigscreen is great and the fact that Twilight lead the way should be celebrated. Others are smart to follow in it's footsteps instead of being left behind :-)