Backward compatibility is very important to me because if I get a 360 I would like to get rid of that huge Xbox from my entertainment center. I've been a huge fan of backward compatibility since the Genesis days when I could play my whole SMS library on my $200+ investment. Plus because of CAG, I have this library of unopened Xbox games I need to play through and if the 360 won't play them then I have to keep my Xbox around a while longer. IMO, the PS2 survived it's horrible launch lineup because it was backward compatible.