Disable smooth scrolling in Preview in Lion
The new menu items Go - Previous Item (⌥↑) and Go - Next Item (⌥↓) aren't animated. They seem to behave like ⇞ and ⇟, but without scrolling documents that don't fit the window vertically. And they always align the top of the document to the top of the window in the Continuous Scroll mode.
They don't have that equally annoying page-slide animation in the Single Page or Two Pages modes either.