SEN also has a runway that is to short so I doubt anything will be diverted there from STN. This is why there are hardly any diversions now with the exception of the odd LCY aircraft. The short runway is the limiter to any expansion which some threaders seem to be unaware of. It cannot service a full 737 or Airbus, this is one of the main rerasons it lost all of its holiday traffic in the 70's.