Dollar gaining against Yen, but the Yen is still only Two Yen Off Historic Highs

It seems modest gains in dollar are attributable to Bernanke's guidance that QE3 may not be coming; also looks like there have been interventions from the Japan and Swiss Central Banks that support the dollar.

http://www.reuters.com/article/2011/08/25/markets-forex-yen-idUSN1E77O18T20110825

But the central banks can, in terms of direct intervention, only do so much; the markets drive most of this. If and when QE3 does come, expect the Yen to gain more.