Here are some other methods I would like to see:
llGetCreator() - returns the id of the creator of the object a script is attached to.
llGetOwner(key id) and llGetCreator(key id) - returns the owner and creator of the object with the ID. Would just return the same key if id is the key of an AV.
Object to Object IM is said to be in the works. For the state for recieveing IMs please pass in the Name, ID and message just like listens. I'm fairly sure that is what is intended, just stating the obvious.
llGiveInventory(key giveTo, key itemTogive, integer COPY | ORIGINAL) which gives an object in the inventory to a specified object or AV. The item in inventory should retain copy/no copy status, so that you can't give a copy of a no copy object.
llGetCopyable() - is this one possible already? Just a way to check whether the object the script is attached to is copyable. Modifable check would be nice too.
I'm sure I will think up more.

[edit] ok that didn't take long...
llGetRating(key id, integer BUILDING | AVATAR | SOCAIL) - returns the rating of the AV of the id, or owner of it.
llGetTotalMoney() - returns the amount of cash the owner of the scripted object has.