yes, i have the FIOS TV also, but like i said above, a coax cable is running from the wall into the router, along with the ethernet cable, and i'm not sure why. My tv's are in other places, and have the coax cable going from the wall to their set top boxes.
edit: got the answer.....after filling out the online question form with verizon, and getting back a couple of useless e-mails with a bunch of links to help topics that didn't even have anything to do with my question, i finally gave up and called them.....they said the coax cable is used to send the programing guide, and the video on demand programing to the set top boxes so i can see that stuff on the tv. it's actually an output cable taking info from the verizon router/nim to the tv set top boxes.