A recent article on the Wall Street Journal site discussed the effect of adding new words to the list of legal Scrabble words. The controversial words are things like "za" (a rare slang term for pizza), "qi" (a Chinese word, meaning life force... a new-fangled spelling of "chi"), and "zzz" (onomatopoeic word for the sound of snoring). Some argue that they make it too easy to use the letters "Z" and "Q", and that their point values should be reduced from 10. Others argue that some of these words are just lame. (It's a good article that also discusses the issues of rule changes in a more general sense.)
Apparently, the way the Official Scrabble Players Dictionary works is that if a word is added to just one of a set of five dictionaries, it is eligible to be considered for the "Scrabble-legal" list. My understanding is that it will be approved as long as it doesn't violate any obvious criteria (hyphenation, proper nounness, foreignness). The virtue of this is that it is an objective approach. I do wonder though how different the list would look if a word had to appear in four of the dictionaries before becoming a Scrabble word.
Should Bananagrams use the Official Scrabble Players Dictionary? Or should it come up with its own dictionary? Is "za" pronounced to rhyme with "baa", or does it retain the schwa sound from the end of the word "pizza"? Do I take every opportunity to use the word "schwa"? (Answer: Yes.)