So, EMA gets 787 operations before BHX. What are the implications? Very little I suggest.
Comparing the 787 with the 763, so far as I can see the seating capacity is little different, and I honestly doubt your average bucket and spade passenger would care whether they were being loaded on to a 767, 787, or for that matter 707 - so long as it gets them to their 2 weeks in the sun. You only have to look at the number duped into flying on that instantly forgetable mob that were used by Olympic Holidays last summer from BHX.
Surely from an enthusiasts basis it's a new (soon to be come very common) type and lots of new reggies to spot - but apart from that, frankly, no big deal.
I don't know, but I suspect that BHX will have a 763 based throughout the summer of 2013 operating to long and medium haul destinations. EMA I suspect may not, so their long haul ops may be on a 787 that positions in and out to operate the SFB and CUN.
I'd say, wait until the BHX runway extension is completed and see the balance of power, long haul ITX wise, gravitate westwards!