Alexandre,
As a conclusion, would accept that we swap (using the regular way) the headers in order to load exe on a Big Endian host? (since the exe headers are Little Endian for each NT implementation)
Pierre
PS : the exe header is Little Endian even on a PowerPC NT exe, since the PowerPC NT implementation was actually running on Little Endian mode, so we won't be able to run PowerPC NT exe on Mac OS X.