Artoomis said:
Now, now - Anubis is right as far as knowing what is "official." Nothing stops you from doing whatever you want in your own game, of course.
Mostly. Except that there is a published heirarchy of rules to be observed and their purposes. The FAQ (as observed by others) is creeping (well, running in some circumstances) outside its terms of reference.
And as the FAQ being rules, let me quote a little example from my own life, which can act as an analogy for the D&D rules set. My previous job for a number of years required, amongst other things, interpretation of legislation. Legislation, analagous to the core rule books, at times is found to have errors in it. Sometimes related legislation (non-core material) has an apparent impact on the core legislation - primary legislation trumps ancilliary legislation, just as core rules trump non-core where there is a conflict.
Corrections or variations (or amendments as their are known) to legislation is undertaken regularly and analagous to the errata.
Underneath the legislation in the heirarchy was a thing called 'the guide'. This was the policy interpretation of the legislation and analogous to the FAQ. And while the guide held a degree of status in a legal sense (much like the FAQ) no amount of commonsense or wishing would allow the guide to trump the legislation - a fact driven home several times in administrative appeals courts.
Often legislation and guide did not necessarily provide the authority, under law, to operate in the way it was planned or drafted. As a consequence, changes to the legislation and the guide were regularly undertaken to improve the clarity and hence operation of government policy.
If WotC want monks to be able to take Improved Natural Attack, then all they need to do is issue errata to that fact. It's pretty simple really. As it stands, I don't believe that by the RAW that a monk can take INA. And based on my real life experiences with legislation, polciy interpratation of legislation, and exposure to administrative (and higher) court decisions, no amount of berating by Anubis will change my mind on that.
However, what I am willing to concede is that given the stance by A designer, I believe that a 'beneficial interpretation' of the quoted clauses could be taken to allow a monk to take INA. That is, while the decision is not as per the rules, no appeals court would overturn the decision as the no-one is being hurt by it (except by maybe various opponents - who may then take out a writ much in the lines of what happened in a recent page of the Order of the Stick

).