Chris, you are totally incorrect. Maybe you need to do a little checking yourself. Cablecard with Tivo does NOT support on demand with "almost any of the major cable providers".
I lived in a Time Warner market until about 2 years ago, TiVo supported 100% of their on-demand programming. I now live in a Comcast market and the support for on-demand is 100% on par with that of Comcast's own boxes.
Comcast represents 54% of the American cable population. Time Warner represents about 18%. My comment that almost any of the major cable providers (72% to be exact) support it is accurate, not even knowing if #3 or #4 supports it. I just got on my Tivo and went into OnDemand. Yep, smooth as butter. Doesn't get much more current than that.
Sorry you subscribe to a non-cable cable provider. Honestly I'd love to have an alternative to Comcast, and would GLADLY give up on-demand (a silly feature I never even use) to have access to FiOS. Only alternative we have here is AT&T uVerse, and you couldn't pay ME to subscribe to THAT junk.
Sorry, but my comment was accurate. I'm sorry you chose FiOS which doesn't allow you to use your TiVo box for on-demand. The alternative is you switch to the cable provider (which I'd guess you have TWC or Comcast if you're part of 72% of American households) if you really want that "amazing" on-demand junk.