The Guardian got it right here:
There is a general election to be won in a couple of years, and how David Cameron and Ed Miliband deal with their economic supremos now may do more to decide it than any other decision they take.
Each leader is saddled with a lethal liability in George Osborne and Ed Balls respectively, and faces a finely balanced judgment about whether to dispose of these gruesome paradigms of impregnable arrogance
The public have less strong feelings about the Shadow Chancellor, presumably because they have the good fortune to know little about Ed Balls. But we mega-nerds who have studied him for years suspect his power to cost Labour a general election more than matches Mr Osborne's ability to damage the Tories.
I see... I think...