I've nearly got this post all to myself...
Found out some stuff - for the diesel ausie x5's.
1. jan 2006 - we will be getting 50ppm sulpher diesel
2. we now have 500ppm, some areas already have the lower sulpher diesel.
3. Europe has now got 350ppm, and will be getting 50ppm in jan 2006
3. Our aussie diesel x5's have a different piston shape (from BMW mechanic here) and maybe a thicker head gasket to achieve our 17:1 vs 18:1 eu spec.(not mentioning mapping differences)
upshot: 2 hard to change, expect full spec diesels early next year.