http://www.bcn.co.jp/press/press.html?no=260
(in Japanese, via latest news article and brief summary at DC Watch today)
Full English translation of the report in pdf via Google can be read here.
So, here is what I've copied and pasted the English-translated full table of the Japanese No.1 market leaders of those:-
So, Canon takes almost all the crowns for traditional digital camera stuff including P&S DCs and DSLRs and Lenses, whilst Olympus is the market leader for the mirrorless (ILDCs). Sony is there for several things, but they are not solely camera related, i.e., these are either audio or video/visual related things. Besides, Sandisk is still the king of memory cards used for the digital cameras.