Yes, MANFOD, the next couple of years will be interesting!
On the topic of the STN/MAN comparison, the gap between the two airports was just over 2 million passengers in 2014 (calendar year). On a rolling year basis the gap has fallen to 1.6 million in the CAA's February stats.
Of course we all know that Ryanair's decision to ground fewer aircraft at Stansted during this winter has been a major factor in STN's explosive growth over the winter. But it is evident from the ACL data that STN will continue to grow faster than MAN in Summer 2015. If this continues the gap between the airports could be under a million by the end of the year. And then all bets are off for who comes out top in 2016.