Even with all the legal consequences promised for divulging secrets it still seems like with that many employees working for Bethesda just one of them has to be a chatty cathy.
if you worked for Bethesda do you really think it would be worth your job (and any future job in the game industry), huge legal fees and fines to drop a secret or two?
and most of the employees are probably not informed on the overall project. for example: an employee in the art department might be doing nothing more than creating wall textures, completely unaware of the plot or questline. it's not like everyone on the team has their hands in everything.
as far as the trademark goes, i'm not surprised. i've always thought the skyrim trademark thing was more of an effort to keep other companies from creating name-recognition than to secure a setting for a future game. if, for instance, Bethesda had not secured 'skyrim', the entire meaning of the name could be changed over a few moths with TV/Internet ad campaigns. think about it. if a company was to run commercials with an expedia.com-style jingle...after a few months, it wouldn't have anything to do with the elder scrolls as far as the average joe is concerned.