This should work as a consistent test for bigendian:
-> isBigEndian = (obj.dtype.str == '>')
Also, I have ported numarray's numdisplay to numpy if you would like to directly display an array in DS9. We haven't done an official release yet (sometime soon) but I can forward you a copy if you are interested.
I would very much like a copy. I've never heard of numdisplay before but am always interested in code that can talk to DS9.
I'm porting RO.DS9. it works but has some rather ugly bits of code in it to deal with the many vagaries of xpa and ds9.