Don't know, but I can guess.
Gateway's had lots of problems recently.
I don't think they sold as many Athlon boxes as they hoped.
They probably went to Intel and said, "Look we're having some troubles. Can you give us a break on pricing?" Intel probably said, "Sure, cheaper processors and more marketing money if you go with us exclusively." They then probably went to AMD and said, "Can you help us out?" And AMD probably wasn't able to counter.
I'm sure it hurt AMD some.
And on the Hammer and nail stuff....
Remember that AMD and Intel have lots of patent, etc., cross-licensing agreements. It wouldn't surprise me at all that if Hammer took off and seemed to be killing Itanic that Intel would work with AMD to license the relevant bits. Though Intel has deep pockets, they can't fight the market. If the market goes AMD in a big way, Intel will have to respond even if that means swallowing its pride on the Itanic.
Just some idle speculation on my part...
Cheers,
Scott.