All, I have  a book I was considering posting, but there is slight water damage on 2 - maybe 3 pages.  It's probably from opening the book with wet hands.  Would this be considered too damaged to post?

If I rec'd it, I wouldn't think twice about it.  It's a very good hard cover book except for this minor issue.

Water damaged books can't be posted.

There cannot be any water damage. If it is a wishlisted book you can list it in the unpostable thread in the book bazaar and ask for a credit for the book.

From PBS Swappability Guidelines: 

Overall Condition:

• No damage at all from water or other liquid
• Not soiled
• No stains (exception for cookbooks--see below)
• No mold
• no highlighting, underlining or writing on text pages (exception for Textbooks/Workbooks and travel guidebooks --see below)

Almost any stain on an older book can be claimed as "water damage"; thus you see quickly there are some real fanatics on PBS these days who expect everything they receive to be in new or nearly new condition. [In my never humble opinion]

[What  I do to combat these people is to post books that seem perfectly good to me, accept the request, then carefuloly and honestly describe  anything that might be alleged to be "water damage." Then ask the requestor to inform me "ship or no ship." Four of every five say "ship" and later I get a nicer "thank you" from them]
 

Neither water damage nor stains are allowed.  By posting the books, you are agreeing that they meet the guidelines.  If they don't meet the guidelines, offer them in the Book Bazaar.  Most of us expect the rules to be followed.