Just announced at the Pentax Japanese Homepage:-
http://www.pentax.jp/japan/imaging/index.php
Direct firmware update and download pages:-
http://www.pentax.jp/japan/support/download/digital/km_s.html
http://www.pentax.jp/japan/support/download/digital/k20d_s.html
http://www.pentax.jp/japan/support/download/digital/k200d_s.html
http://www.pentax.jp/japan/support/download/digital/k10d_s.html
(All pages in the above URLs are in Japanese)
There is only one change for all the above firmware updates, though. That is, to "improve the stability of SDHC cards for photo recording". It is not really an exciting update with no new functionality after all but it is still good to see Pentax does support their old product to ensure better compatibility with new SD cards even for a really old product like the K10D which was discontinued years ago.