Most writers here know what story paths are about. Yes? We merely change subject matter. Adventure paths are merely an extension of basic grammar to start if you go basic English, alone.
If we look to the Paizo post, we see..
"Most Adventure Paths don't allow, or accomodate crafting, thus nobody wastes a feat on that,"
...as an example.
I see lots of trouble if they try to defend it due to the notion that you are able to claim a general term (corn flakes, bread crumbs, etc..) as a proper term (Corn Flakes, Bread Crumbs, etc..). Kelloggs is on record as trying the same thing - the notion fails to win over the courts, so far.
"A non-final action has been mailed. This is a letter from the examining attorney requesting additional information and/or making an initial refusal. However, no final determination as to the registrability of the mark has been made." This is the current status of the claim.
Is Paizo claiming to own a term that is not final? I have a serious problem with that one. Companies that do end runs around legal systems rarely WANT to find themselves in arbitration, first off.
http://www.uspto.gov/web/offices/tac/tmfaq.htm
"Can the Office refuse to register a mark?
Yes. The Office will refuse to register matter if it does not function as a trademark. Not all words, names, symbols or devices function as trademarks. For example, matter which is merely the generic name of the goods on which it is used cannot be registered.
Additionally, Section 2 of the Trademark Act (15 U.S.C. §1052) contains several of the most common (though not the only) grounds for refusing registration. The grounds for refusal under Section 2 may be summarized as:
1. the proposed mark consists of or comprises immoral, deceptive, or scandalous matter;
2. the proposed mark may disparage or falsely suggest a connection with persons (living or dead), institutions, beliefs, or national symbols, or bring them into contempt or disrepute;
3. the proposed mark consists of or comprises the flag or coat of arms, or other insignia of the United States, or of any State or municipality, or of any foreign nation;
4. the proposed mark consists of or comprises a name, portrait or signature identifying a particular living individual, except by that individual's written consent; or the name, signature, or portrait of a deceased President of the United States during the life of his widow, if any, except by the written consent of the widow;
5. the proposed mark so resembles a mark already registered in the Patent and Trademark Office (PTO) that use of the mark on applicant's goods or services are likely to cause confusion, mistake, or deception;
6. the proposed mark is merely descriptive or deceptively misdescriptive of applicant's goods or services;
7. the proposed mark is primarily geographically descriptive or deceptively geographically misdescriptive of applicant's goods or services;
8. the proposed mark is primarily merely a surname; and
9. matter that, as a whole, is functional."
Between their "Technical Director" making a very public claim which is technically false at this time on the Paizo forum and the claim being very general in usage with no distinctive name (Bob's Uber Fun Adventure Path for example), I think any party that wants to fight them on it stands a reasonable chance under reason 6 for denial of registration. On the other hand, Paizo has an easy out - register Paizo's Adventure Paths instead of a general term in print (the subject matter and class of trademark).
Of course, I am just a newby clerk type - I suggest hiring a trademark lawyer before going to court over it. <- Usual Disclaimer