From a line pilots perspective... the 318 has always had the smell of having been agreed to in a weak moment. Plenty of cheap and cheerful equipment was already in place to fly any regional operation, so methinks there was some back-door Airbus-led discounts given to get the mini-minibus on the marketplace.
What BA really need is a medium-high density 757 replacement (assuming you accept the argument that he 757 has to go... read into that what you will) in other words, a few 321's to cover the shuttle routes at peak times and the high yield European stuff, which we are still doing very well on, despite the bad-mouthing in here and elsewhere.
There were strong rumours flying around about some deferred GB 321's coming the mainline way recently, but nothing concrete.
£6