Update suggestions (among others):
-Fix the Treehouse and LOG CHALLENGE (!!!)
-Allow people to mail multiple items at once (!!)
-Canoes (!)
-Fix the shop glitch once and for all (!)
-Prize at the end of D2 (or else remove D2... but I'd rather keep it)
Again, these are just the first things I'd focus on. There are several other ideas, but I think these should be considered first.