Hypersmurf said:
Of course, there are a few spells in the Spell Compendium that refer to a 'natural weapon or unarmed strike', just like several places in the PHB.
This tells me that a natural weapon is not an unarmed strike.
-Hyp.
I guess the difference to me is that one is exclusionary, one is not. For instance, it would be somewhat strange, but I could say, I like fruit or apples for breakfast. Or, I could change it up and say I like fruit or bread for breakfast.
In the first case, apples is a subsection of fruit. In the second case, they are unrelated.
However, I could not say, I like fruit, such as bread, for breakfast. However, I could say, I like fruit such as apples for breakfast.
So when the description for Magic Weapon says
You can’t cast this spell on a natural weapon, such as an unarmed strike it is absolutely including "unarmed strike" into the overall category of "what is" a natural weapon.
However, as a subsection of natural weapons it does have some of its very own rules that govern its use.
Back to my example Apples do not share all of the same traits as other fruit, however, they are still considered a fruit.