I don't own the books YET (damn you amazon... DAMN YOUUUU) but i was looking around Borders this morning, trying to fend-off my inpulse buy reflex on the new books. I would have buckled if they had the gift set in stock (since I have a 30% off coupon but I can only use it on ONE item) sadly, that was not the case. And after looking at the books, I definitely don't feel the DMG is worth $35. Sorry, WotC. I'll take my amazon 45% discount, thank you.
Aaaanyway, I noticed every single 4e book on the shelf had at least mild warping on the pages. On some, it was fairly noticable to the point where they almost looked well-used, but no, these were brand new books on the shelf. I picked some up and opened them, and the binding had that familiar 'crack' of being opened for the first time. So they definitely weren't copies that had been heavily perused by curious would-be buyers.
P.S. - as i answered in the poll, humidity here in San Francisco is now hovering around 65%.
Anyway, WotC, I'm not sure what the deal is. It is fairly minor, but annoying. And makes me question the quality of the paper stock and/or ink used on 4e, because I don't recall this being such a widespread issue with the 3/3.5e books.