I think the List object is too generic to be considered a 'building block' like any DOM element, and it lacks customization.
I think we could have something like a 'grid object'. A object where the user could customize things like number of rows/lines and its respectives width/heigth, and background texture like 9patch. And the user could attach sprites and text/spritefonts objects inside the cells at runtime. And it would handle scrolling, with the option to customize its sensibility and speed.
I think it would help in 90% of UI complex issues. Would be a powerful building block that could be used in things from simple leaderboard tables to complex inventory systems