Congrats and Welcome!
Moon Palace is great, but YES they have a reputation for being slow on responding. They do so many weddings that I think they just get behind. From what many others have said, once your bog day rolls around, they are on top of things and have everything worked out the way you want it! Don't sweat it. If you start getting REALLY antsy, give them a call. We ended up doing that in the end to make sure they didn't give the slot we wanted away. We got a response pretty immediately, and anytime we had a question we called and got a response by the end of the day typically.
While you are waiting, check out all the slide shows of weddings at MP! I have gotten some great ideas, and love seeing the rooms/ceremony/reception/resort locations.
All the ladies on both the Moon Palace 2011 Brides and Moon Palace 2012 Brides are more then willing to help you out with any questions you have. Happy Planning!