In combat, there's a new command "Log" which shows the message log. This could be handy when you want to review what happened during the last round of a fight. To show it, you can click the "Log" button, or use the "L" key as a shortcut. It can be closed with the escape key, by clicking the cancel button, pressing the "L" key again, or "C" for cancel.
When using the "Trade" or "Swap" commands on the character sheet, the target character's name will be shown below the number used to select them. This could be handy when you're not sure what position another character is in.
Buy/Identify buttons will be grayed out in shops when a character doesn't have enough money to pay.