There was already a post in Japanese about it so I wanted to post some information in English as well (although a bit late).

Over the weekend Japan launched its first ever GPS satellite that will help to get better accuracy in the concrete jungle of major cities and in the mountains.
From what I hear the service won't be available for mere mortals until 2013 tho.

For more information check out these news items.

BBC news article -> http://www.bbc.co.uk/news/world-asia-pacific-11273982
JAXA launch MICHIBIKI via HII-A launch vehicle -> http://www.nasaspaceflight.com/2010/09/jaxa-launch-michibiki-via-hii-a-launch-vehicle/
The official Michibiki site -> http://www.jaxa.jp/countdown/f18/index_e.html