I'd rather have something like this in a book format showing what is where, the possible drop rate on items the monsters/mob carries more so then an in game thing. Having it personalized as an add-on type deal would give skewed results.. well percentages are generally skewed anyways, but if its in a book format then its available to everyone with the same data in it, also having it as a downloadable phone item, etc would work. Thats just me personally, but yea it is a cool idea.