I have both, and I don't think they are too similar. Surely they've got the same form, as in large display, no keyboard, but the iPhone wasn't the first phone with this design.
Otherwise the look&feel is different.
Plus, the border of the original Galaxy S is black, makes a significant difference. Not much room for innovation in a candy-bar touch screen, really.
I'd side with Samsung on the legal argument, as well. Apple is known as very secretive, Samsung announces products FAR ahead. Saying that Apple hasn't announced their products essentially penalizes Samsung for being open about what they have in the works, and announcing and showing their products early. If Apple plans to release the iphone5 this summer (and if history is an example, they do), wouldn't this be the same argument that Apple used?
I'm not a lawyer, but punishment based on pr schemes seems weird to me.
