BHX has good short haul and transatlantic links
If a "not quite daily, year round" operation to Newark NJ constitutes good transatlantic links then that must make the twice daily all year round operation from Dubai positively stupendous!
BHX has abysmal transatlantic connections, and actually scores better in the oposite direction, with not only EK, but also PIA and Turkmenistan offering regular services.
The problem with BHX being the answer to LHR's capacity problems is that "London Airways" has no interest whatsoever in developing European, let alone long haul service. Virgin seems similarly disinterested.
Until the "Londoncentricity" of the UK is reversed I'm afraid that all other cities, and their airports, will be under used.