UPDATE: translation of TEPCO's email to the members of the press who have signed up to receive notification of emergencies is posted in this post. It's not for so-called "mass media", it is for any journalist who has signed up for the notification from TEPCO." In fact, I got the link from an independent news media.
Again, it is NOT the water level of the SFP but of the skimmer surge tank, as some people are clearly confused that SFP's water level is dropping.
From ANA (Asahi TV) News (1/1/2012):
Water leaking in the facility adjacent to the Spent Fuel Pool in Reactor 4 in Fukushima I Nuclear Power Plant?
It has been confirmed that the water level is getting lower in the tank adjacent to the 4 Spent Fuel Pool in Fukushima I Nuclear Power Plant at a pace 5 times faster than normal. TEPCO is trying to identify the cause as soon as possible.
At 5:30PM on January 1, the water level of the "skimmer surge tank" next to the Spent Fuel Pool in Reactor 4 was found to be going down at a relatively rapid pace. The water level goes down due to evaporation, but the speed was 5 times faster than the rate of evaporation. No leak has been discovered in the SFP's cooling system or around the reactor building. The cooling of the SFP continues, and there is no change in the temperature and the water level [in the SFP]. TEPCO is conducting the inspection of the pipe joints, trying to identify the cause of the dropping water level in the skimmer surge tank.