Dawn, you hit the nail on the head (amen, amen and amen!) with that. Let me add my two cents worth:
Personally, I think deadlines kill creativity. I've said that many times, and I acknowledge it's a viscous cycle. You write a book that's inspired, entertaining, popular and a huge success, and suddenly the world wants more...more...more...now...now!...NOW! How can anyone create good work under that kind of pressure, let alone a sequel that's half what it could be, or what fans expect it to be?
A blog I frequent recently posted a link to another author's blog who is in such a situation. He's had to push back the deadline on his next novel, and apparently his "fans" are getting downright homicidal about it, and putting him under tremendous pressure. He wrote a bit of a rant just to vent on his frustration at the situation, and I completely relate to his feelings. Why would fans do this to a writer? Personally, I give him credit for sticking to his principles and refusing to kick out something by the required deadline when he knows it's going to be a disappointment. And of course the irony is, if he did cave to pressure and turn out a second rate piece of work (as, unfortunately IMHO many authors do because they are trying to force their muse to meet the demands of their budding career) then the same fans clambering for the sequel would probably crucify him. It's a Catch-22 if ever there was one.
But there's the dilemma. How do you build a career if you don't do what's demanded of you by fans, editors, publishing houses? The wheels of the industry turn on the ability to supply on demand. When you're dealing with all of life's other priorities and deadlines (like, most of us have to work for a living, because let's face it, few authors make enough to support themselves) how do you produce quality work when the pressure makes your muse dry up? What's the answer? Is there an answer? Maybe not, judging by the state of so many sequels I've read.
John Scalzi posted this on his blog. I think it frames some of these issues from a popular authors's POV.
Now we're on a roll.