Not sure that the 777 order means anything other than BA adding some handy capacity...
I suspect though that Boeing are still in the driving seat for the main order...they would love to have another big blue-chip 747-8 customer, and will probably offer a fine deal. And in that sector, Airbus have nothing to offer; the A380 is too big to be a widespread 744 replacement...
On the negative side, if Airbus go for broke, and offer BA a fantastic deal on A350s, will Boeing cut their margins on the 787 to win the business? I suspect that if BA want the 787, they may have to pay going rate...with the US majors expected to order soon, Boeing may prefer to sell to customers willing to pay a bigger margin...
Finally, will the 787-10 come into play?
Exciting times...