The fact is that the more high profile recent releases are being released region free.
It has been suggested on that thread that Conker is also region free (still unconfirmed).
Which then leads ...
Could it be that the NTSC & PAL default.xbe's are exactly the same? A lot of games are being released that are region-free (i.e. you can play the NTSC version on an unmodded PAL xbox).