I would like to see tile markers for ranged attacks, something that would let me know when my hunting bow is in range.
@ Jeff & BG, you can also go to the dropdown menu under "Display" (to the right of the quest name) and check "Show coordinates."
I'm with Maeglin on this - the info is already there in your action-selection screen.
Along similar lines, or possibly what this poster meant: I can see the range of my weapons and skills (granted, I have only tried one class), but when the grid doesn't show up well on the background, none of that knowledge helps. I have to roughly eyeball to see if I can, for example, back up and still shoot.
You know when you're in range for an attack when it shows up as an option in your actions box (it only shows the abilities that can be used).
The ability and attack descriptions already contain range information, visible when you click on the ability name on your character.
Jay Turley commented
I'd also like to see range information in the ability and attack descriptions as well. I had no idea which ones could be used 1 square, 2 squares, or more away.