The change is primarily about the ALP's perception that they are dead in the water now under Rudd and that Gillard is a better choice. Secondary is obviously the Rudd style of leadership within the ALP.
If Gillard is elected, she will be a harder opponent for the opposition undoubtedly, whether that is enough to change the ALP's standing in the polls we won't know for at least a few months to be honest.
The female factor will be an interesting one and how that plays out. It changes the tactics that Abbott will need to employ. She isn't a light weight despite what you may think about her politics. Her past about being a communist, unionist etc is irrelevant. As was evidenced by the Lib campaign at the last election about the predominance of union members on the ALP front bench. That didn't cut through at all. As will any commentary about the union influence, faceless faction leaders as king or (queen maker) if JG is elected.
Given Gillard was (based on what has been written in the media) was one with Rudd on many of the big issues, how well this can be expolited by her political opponents will be one of the key factors in how she is viewed by the electorate. Or is she another Christine Keneally? She is going to have to change the current ALP policies eg RSPT
Assuming a November election, 5 months is an eternity in politics. Watch the ALP machine, re-write the Rudd history over the next few weeks and months. His legacy is already being pooped upon by his own party.
I wonder what Peter Costello is doing today?