Toshiba issues a brief message stating that the SED TV launch is not going to happen in Q4 2007.

Toshiba says that the decision is based on information provided by Canon, indicating that Canon cannot provide SED panels in time. Toshiba does not give a new launch date for SED (Surface-conduction Electron-emitter Display) TVs.
2004 Toshiba revealed the first time plans on developing an SED TV. Back then, the company already said to ship SED TVs in 2005. In 2005 Toshiba and Canon touted an SED TV with a staggering 100,000:1 contrast ratio. There was no rollout though. In early 2007 expectations ran high that Toshiba might show SED TVs at the CES 2007, but it did not happen. I am not sure if just the patent lawsuit between Canon and Nano-Proprietary is to blame for the delay.
Maybe other TV technologies just got much more attractive in the meantime like OLED, FED or Laser TV.

Via the Toshiba site.