Everyone reads differently and looks for different things in a reading experience (if you couldn't already tell by the comments). I remember once when I was in elementary school, a teacher suggested to kids that were having trouble focusing or who were losing their place that they should use a piece of paper to obscure everything below the line they were reading and slide it down the page as they went. For reading on a screen, reflowing and resizable text can helped greatly with focus and "losing place" problems (I love Readability), but the "scroll line" concept you've got here has the potential to maybe go a bit further.
I think that if you blanked out everything below the scroll line, or everything below a good-sized margin of it (so as to preserve some of the text from the previous "page", to enable a bit of bouncing back and forth), you'd have a pretty good, functional recreation of that, and some people might find it pretty useful.
Everyone reads differently and looks for different things in a reading experience (if you couldn't already tell by the comments). I remember once when I was in elementary school, a teacher suggested to kids that were having trouble focusing or who were losing their place that they should use a piece of paper to obscure everything below the line they were reading and slide it down the page as they went. For reading on a screen, reflowing and resizable text can helped greatly with focus and "losing place" problems (I love Readability), but the "scroll line" concept you've got here has the potential to maybe go a bit further.
I think that if you blanked out everything below the scroll line, or everything below a good-sized margin of it (so as to preserve some of the text from the previous "page", to enable a bit of bouncing back and forth), you'd have a pretty good, functional recreation of that, and some people might find it pretty useful.