I think the definition of "full frontal nudity" may be at issue. Now, personally, unless...well...the full Monty (or, er, Montina) is revealed - including areas below the waist - it's not full frontal nudity. I suspect this is Matthew's/Mongoose's definition as well. If only the areas above the waist are revealed, the lady in question is simply topless. You get that sort of thing in certain of White Wolf's products as well, and no, I don't mean their Black Dog books. Have you had a look at the Scarred Lands DM Screen Companion?
I don't believe any of the images referred to above feature actual full frontal nudity by that definition, nor do I think that any of the images in the book, period, feature it. I don't have the book handy at the moment, but I'm pretty sure I'd remember something like that.
Now, I can't say I'm terribly pleased with the images, and I'm not really sure I understand why they're there - if they're meant to attract *ahem* a certain element of gaming society, it's rather silly to bury them halfway through the book. Why not simply go the Avalanche Press route and stick them on the cover? I would like to know why the rather gratuitous cheesecake is present, yes.
However...it's not as bad as you're implying. If "topless" is your definition of "full frontal nudity," so be it, but you should know that not everyone goes by that same definition.