Under the existing rules, if a bag is lost or damaged, passengers can ask for a refund of the fee as part of their claim for lost property. If the bag is just delayed there is no recourse for the passenger, even if he has to purchase necessities.
We will be hearing details of the new rules later this month. The rules will address baggage as well as other proposed changes, including payments to bumped passengers, no-penalty cancelations and improved fee disclosure. The DOT wants to make airlines pay passengers more when they're bumped off their flight, allow passengers to cancel reservations within 24 hours of booking with no penalty and require better disclosure of fees and surcharges.