In AutoCAD 2012, as you key in commands, AutoCAD will automatically complete the entry for you. If you pause, a list of all possible commands and system variables are displayed for easy selection.
You can customise AutoComplete from the command line right click menu, even controlling the delay response time.
You may have also noticed that the command history is now displayed with a grey background colour by default. This can be modified in AutoCAD Options > Display TAB > Colours.