When the user is told they have to pay a fee because a transaction has low priority, it'd be nice if the client calculated how long they'd have to wait until the inputs have matured enough to have high enough priority so they DON'T have to pay a fee.
Suggested by bitlotto on the forums.
Or for that matter asking whether or not they even wish to pay the fee. Sometimes people don't need their low-priority transactions to be higher priority.
Although I'd like the wallet UI to be more transparent about fees, the fee system (and expectations around it) changed enough for this specific request to not make sense anymore.