Thought it might be useful to consolidate the various threads so far and when Members find out how individual airlines are applying the revised rules at approved airports, they could post here and so keep it updated in the hope it might help passengers confused about their forthcoming flights.
WorldVoyager's advice to contact your airline if in doubt still holds good though.
BA - One bag no bigger than 56 cm x 45 cm x 25 cm (22 inches x 17.5 inches x 9.85 inches) (including wheels, pockets and handles).In addition, one briefcase or laptop sized bag.
The maximum bag weight is 23kg and you must be able to lift the bag into the overhead lockers in the aircraft cabin unaided.
Easyjet and Ryanair - are still rigorously enforcing one bag.
Etihad - 2 bags each of standard size (like BA) but maximum weight 7kg each.