There's a lot of anti-sidescrolling sentiment in this thread... which I find odd considering how common place sideways gestures are on touchscreen devices.
I'd say that sideways scrolling has a big future ahead of it and in a lot of cases is better than having to press prev-next buttons.
Gestures are one thing, scrolling is another. To get a look at the immense difference in usability, check out an app like flipboard vs feedly, one uses vertical-scrolling and the other uses side-scrolling. I very much prefer the vertical scrolling, but I won't speak for everyone, just giving an example to try out.
I'd say that sideways scrolling has a big future ahead of it and in a lot of cases is better than having to press prev-next buttons.