Heh. Without knowing the images, I guessed that the old version was a blurry old 35mm photo and they wanted something higher resolution. That would be an interesting question - is a technically superior, but similar looking, image still a copy? But that is not the case here.
If the former were a trade mark, I think the original photographer would win easily (although perhaps not for $2.5 million). The new picture is obviously done to replicate and look like the old one.
But copyright? I dunno. Seems like a derivative work, though.
Las Vegas Show http://www.caesarspalace.com/images/Property/clv/events/RodS...
They are quite similar.