As someone potentially affected by this I can say it’s somewhat disheartening. Looking at it from a pragmatic standpoint I understand the desire to prevent “WP” from being mis-associated. In our particular case we’ve used WP at the beginning of many of our PlugIns to identify them as being available specifically to WordPress as opposed to some of our other projects that are not. With so many other PlugIns in the repository using “WP” as a prefix to their name and with no public information on it being grounds for rejection we put a lot (and I mean a lot) of effort into building our core PlugIns and add-ons around that naming convention. Thus far it hasn’t been stated as a reason for rejection, but we had to stall out after our initial submission because of a series of events. We’ll be resubmitting in the next week, maybe they won’t mention it.