Flipping Humbuckers

I flipped my neck humbucker so I could have reverse zebra/regular zebra, there's absolutely no difference to the sound at all, or if there is then its barely noticable.

I checked up on this before I did it too and everywhere I looked said no difference because its all just wire wrapped around a magnet anyway, doesnt matter what way round it is.
 
I think I have seen reversed emg's sold, 81's I think... Maybe some hums have different windings or parts dependent on the strings they are under?
 
Dime flipped his pickup because one of the blades was hotter and had different characteristics than the other.

However, on most humbuckers, both blades/coils/whatever are the same.

From the DiMarzio site:

Does it matter which direction I install my pickup?
Most humbuckers are symmetrical and their sound does not change at all when installed backwards, but some have a slightly different sound if you install them in the opposite direction from normal. It’s not a matter of right or wrong, but a matter of taste for such a subtle difference, if you can hear the difference at all. Those models include the Air Norton™, Air Zone™, Evolution® neck, bridge and 7-string, FRED®, Humbucker from Hell™, DLX Plus™ neck and bridge models, Virtual P-90™, Blaze™ neck and bridge models and Tone Zone 7™.
The Steve’s Special™, the Bluesbucker® and the MegaDrive™ have distinctly different sounds if you turn them around, and there is no ‘right’ installation direction. The Bluesbucker® is brighter-sounding with the adjustable screw coil towards the bridge, while the MegaDrive™ is brighter-sounding with the adjustable screw coil towards the neck. The Steve’s Special™ is brighter-sounding if the coil on the pickup’s cable exit side is toward the bridge.

And no, as far as I know, the reverse pickups EMG sells are the 89's.