I think we might be disney twins.
Are you planning on booking a package or just getting room and tickets separately? If booking a package, you can generally change things before final payment, but they do have the option of charging you a fee (though both times we changed our package they didn't charge us...once we decreased what we were paying, and the next time we increased it).
If you book a hotel now, just be sure to read through their cancelation policies, be sure you understand what you are getting when you book it, and depending on what the policies are, you could most likely change or cancel it if something different comes up later.
Now that you know you love it, you are going to get APs on your next trip, right? Assuming you didn't do it during the trip? Get them for next December, then plan another trip that falls totally inside 365 days from that trip, and you've got two yearly trips on one AP, which is going to be a better deal than tickets twice, plus you've got the discounts on food (and merchandise if you get at least one Premium AP) (just watch out for blocked out days with the Deluxe)
We got there right after the Candlelight Processional madness as well as the two CM party nights where they close DL very early. Crowds were very doable until the 9th, when things started to get more and more crowded as the weekend approached. Others have said that the next week was fine, but to me it didn't LOOK like it was going to be fine, it looked like it was going to be more crowded.
But until we find someone who was there BOTH weeks in '07 we won't know a good comparison.