I for one can't read Facebook's timeline and that uses downward scrolling. I don't quite get why I find it so difficult. I really can't get on with it. I'm fine with one column (but two - is a complete mind warp for me.)

It's probably an alignment issue with my brain scrabbling to differentiate content.

I'm also a fan of paging over scrolling. So it will be interesting to feel how this works. Perhaps scrolling with the finger lets you focus better than scrolling with the keyboard or pointer.