This has been discussed countless times, it's not a new rule, it's the implementation of a rule that was passed in April of 2011, with quite a few threads discussing it over the past however many months.
The total price display I think is the least significant portion of it. While it would be nice to see the total price up front, it's really not a big deal to make the extra click or two to get the total price. Maybe somebody who has never traveled before thinks they can go to London for $99 each way and only have to pay $198 and needs to be told the real charge is much higher up front, but anybody else already knows it.
I think the other parts of it are way more significant, but of course the focus will be on the saving those extra mouse clicks.