In this article on Business Insider, the American TV watching trends are showcased. The author notes that the same thing happened to newspapers in a similar fashion - the drop off in revenue happened very quickly.
400K people have dropped pay TV in the first half of 2012.
VZ launched FiOS in 2004 with service turned up in 2005. After 7 years and billions of dollars not just in fiber rollout but marketing, CPE and installation, VZ has finally hit 4.5 million TV subscribers. ATT is still behind Charter with 4.1 million.
You would be better suited to bundle a Netflix or Hulu Plus or Amazon subscription into your broadband service. Or go the hardware route and sell Boxee, Roku and other devices that allow for streaming Netflix, Amazon, Hulu, Pandora.
A head-end will be expensive and the content will be even more expensive to compete against DirecTV or DISH, both of whom would gladly pay you for sign-ups.
FYI, FiOS TV is not IPTV, but regular QAM transmission. There widgets run on IPTV, though. ATT U-Verse is IPTV.