UI2 and eventually 3 should scroll up/down with 1 arrow, flipping pages every 10-15 seconds.
Currently UI2 doesn't scroll repeatedly when 1 arrow up or down is displayed in lists... In my opinion this is a a major usability improvement - LinuxMCE users could display enormous lists of media in a slower to render, fully automated yet comprehensible manner. Right now, its hard to follow everything on-screen with lots of varying media in a 2 arrow flipping mode.
If 1 arrow up/down is not meant to flip by design, then I would suggest 2 arrows should scroll through lists slower by default.