Ah, always the rebel, eh?
Think about it though...the reader wants continuation, so if the same character keeps changing from book to book he/she will likely lose interest.
I read many Star Trek TOS books and loved how each book delved deeper into the character's personality, without truly changing anything about the people I had come to care about.
We know those characters from the movies and series, but if we create a whole new set, as matsamu proposes, we will have to make some basic decisions as to who each character is capable of being or else chaos!
Glad you're back WCA, where were you?
Tyger