Well they certainly won't be needing them for the regions. Think of all the routes the 787 could do that the others (744 & 777) don't at present. I believe Austin has been announced for next year from LHR. If there are other long haul routes (presumably BA bought them for just that) in mind then may be with the 900 version a direct Perth would be considered? I guess the 800 version can do Jarkarta or KL in the Orient, or maybe Indianapolis or Denver in the USA.