http://bugs.winehq.org/show_bug.cgi?id=13819
--- Comment #6 from Andrew Zabolotny anpaza@mail.ru 2009-06-15 03:58:16 --- This is a case of program generating incorrect results in a perfectly valid situation, so I'd classify this as a bug.
Perhaps GetConsoleOutputCP() should call some method of the driver, and let the driver decide what's the correct console codepage. I have the same bug with my linux console using UTF-8 (or CP1251) and GetConsoleOutputCP() returning 866, so any cyrillic output I see is in incorrect encoding (just run 'wine cmd').