Well, my vote is an obvious continue on to book 2.
I understand if you have desires to run another game and as Toric (my f2f DM) can attest, I've always told him to do what he finds most enjoyable and fun. Therefore, run what you enjoy and find fun. If you can't please yourself, then I'm a firm believer that it will show in the game and more importantly you'll be cheating yourself.
NOW....
If you're asking straight up for my opinion, I would love it if you cracked open the cover of an empty book and continued writing this great story. Scarce are the games in which I feel as close a connection to my character as I do in your game. And scarce are the games that last with participation from the players and GM for as long as this game has. In truth, this game is the
SOLE reason I still frequent EnWorld.
If you decide to shelve this one after this chapter ends, then I shall applaud you and my fellow players for a well run, exciting, and fun game and story.
If you decide to keep running, then I shall commit to playing the game until it is in fact officially ended. I think that the group is well rounded, has a great history, and compliments each other. (Yes even the newbie runt.
)
So, take the time you need to decide and weigh everything. Don't rush to a decision that will cheat you. We've got plenty of time until this book ends..... right?