Dustin Curtis (an up and coming favorite blog of mine):
Android does prioritize scrolling to some extent now, but it still doesn’t feel as smooth as it does on iOS. An inordinate amount of time went into perfectly designing the physics simulations performed by iOS’s elastic scrolling and other touch event responses. Android’s initial development clearly did not include this attention to detail, because issues regarding the user experience appear to have been beyond the scope of the original vision. As a result, the fundamental engineering choices made during the initial stages of building Android’s interface layer were flawed. This is why Android feels “wrong” to so many people.