Mrs Ed Balls, Yvette Cooper, has been playing the long game, or so the evidence strongly suggests.
First, in the Labour party leadership contest, when one or the other would stand but not both, it was decided that Ed B would be the candidate from that household. If he had won (which must have seemed unlikely, even back then) Yvette could have pulled the strings from behind the scenes.
Ed B is now a "busted flush" and cannot credibly re-stand if there were to be another leadership selection, especially as it is now Yvette's turn, so to speak. It would be easy for the lady to make a convincing argument, should there be any dissent from hubby.
Now, it must have been obvious within the upper echelons of the Labour party that the Trade Unions were going to ensure that their man, Ed Miliband, was selected as leader - and so it proved, with the Union votes the only ones putting Red ahead of his brother David. The idea was transparent enough, and has been articulated elsewhere on several occasions: Red's job was never to win a future General Election and get Labour back into power.
No: his task is to ensure the Union's plans for reform of the Labour party are put in place, so that they run the party in future. Once that is done, he can be discarded and a replacement who does stand a chance of propelling Labour back into Downing Street can then be allowed to be put in place. Yvette Cooper, knowing all of this, has been manoeuvring recently, including holding a succession of interviews with carefully chosen newspaper reporters.
In these, her manner comes across well: Ms Cooper is well versed in the art of charming people and saying the 'right' things in a way that will appeal broadly (though not to those able to see through the smoke screen). Her speaking has apparently been voice-coached recently as well, which is a clear sign that the lady means business! All this activity is touched on within this multi-topic column in the Mail.
So, keep an eye on Yvette Cooper. The time is approaching when Red's actual job (as distinct from the purported one) will be complete and he could well be pushed aside, despite the technical difficulties under Labour's party constitution and rules. I still think the local elections next May will be the public (and broader party membership) excuse for booting him out, but the real reason will be that he is no longer needed or useful to the puppet-masters behind the Labour party.