I don't ever remember any rep saying four cameras line. Maybe three but no way four.
And looking at Canon/Nikon line, I really don't think it is understandable at all, Canon is mostly OK (but what the heck is that APS-C EOS-7D near FF 5D ?) and Nikon is total crap (D3X,D3,D700,D300s,D90,D5000,D60,D3000).
Huh? From D3X to D300s is weird but understandable, the rest is crap).
Officially 8 cameras produced by Nikon... lol.
http://imaging.nikon.com/products/imaging/lineup/digitalcamera/index.htm
PS: it doesn't make Pentax line transparent, just not as muddy as one might think.