Reuters covers the Japanese government announcing a 25% power cut for big power users in Tokyo.

UPDATE 2-Japan sets power targets to avoid summer blackouts

Fri Apr 8, 2011 8:05am EDT

* Govt plan aims to avoid blackouts when power use peaks in summer

* Seeks 25 pct cut for big power users in Tokyo, north Japan

...

The government estimates that, with a particularly hot summer like last year's, peak power production could fall short of demand by as much as 18,300 MW in the two utilities' service area -- or about one-fourth of total demand -- after a massive March 11 quake and tsunami shut down several big nuclear and thermal power stations.

Will there a mass exodus of servers from Tokyo Data Centers? Most likely not as moving data and servers is tough. But who would want to plan a mass deployment to Tokyo.

The ministry's proposal requires big manufacturers to submit power-saving plans, such as adjustments to operating hours, and would subject them to modest penalties of 1 million yen ($12,000) if they fail to reach the targets. They could also be publicly identified as not meeting government requirements.

This could be good news for Taiwan, Hong Kong, Seoul, and Shanghai data centers.

Maybe Tokyo data centers can get exemption from the power-savings, but all of this creates more risk and potential more time on back-up power systems.