While I doubt that Roll20 wants to go down the road of MapTool with its macro insanity, I for one really would like to see inline die rolls. For example, in MapTool, one can write "/me attacks the goblin for [1d20+8]!" and it comes out as "DragoonWraith attacks the goblin for 16!" Importantly, the 16 would be highlighted, and display a tooltip on hover that shows the actual die rolled and how it came up (e.g. "1d20+8=8+8=16").
I realize that this would mean parsing entire statements; /inline and /inlineme might be appropriate so that not every single thing someone says has to go through a parser.
It should also probably be a feature the GM can turn off; I've met a few GMs who really couldn't stand it.