5th Gen vs 5.5 Gen

Amazon.com can call the newer 5th Gen iPods by any name they want.
I'm not about to start a campaign against them. If they want to ignore Apple's official nomenclature for their own marketing purposes... that's their choice.

My point above was that according to Apple, the manufacurer of the iPod, there is no such thing as a 5.5 Gen iPod. Apple has chosen to designate the newer 5th Gen iPods as 'Late 2006 5th Generation iPod' in order to differentiate between the two 30GB models.
http://docs.info.apple.com/article.html?artnum=61688

If you ordered an 80GB iPod, it's a Late 2006 5th Gen iPod.
If you ordered a 60GB iPod, it's an original 5th Gen iPod.

If you ordered a 30GB iPod, check the serial number to determine your iPod's generation here:
http://docs.info.apple.com/article.html?artnum=61688#ipodfifth2

There is no 5.5G iPod. The new 5th Gen iPods are 'Late 2006' model 5th gen iPods as officially designated by Apple.

The Late 2006 5th Gen iPods have a brighter screen, longer battery life, a new search feature, and are available with an 80GB capacity.

Hmmm...

And yet it seems that Amazon.com (a company approaching 4 billion in sales this year) is marketing the new iPod's as "(5.5 Generation)".

My guess would be that this is a simple and effective way so that their customers know that they are getting the latest features.

Well, Amazon is wrong. Simple enough. In the past, they've also marketed the 5th Gen iPod as a "Video iPod" when it was first released. Just because they're a large online retailer, that doesn't mean they are without flaws.

My guess would be that this is a simple and
effective way so that their customers know that
they are getting the latest features.

Agreed. Because despite being marketed as the same, as you've explained, there are differences that cannot be implemented into the 'previous' 5th gen by software alone.

Calling both 5th gen is going to cause confusion.

Matt