The LNP, with Turnbull as frontman, will be campaigning on the Abbott government’s record and policies. Apart from a few symbolic and rhetorical shifts (the re-abolition of Knights and Dames, for example), Turnbull has neither deviated from, nor added to, Abbott’s policy program.
There’s a notion being pushed in the media that a big win for the LNP would constitute a mandate to “let Malcolm be Malcolm”. This is nonsense. A mandate isn’t a free pass. It is, literally, a command, to implement the policies on which you have campaigned 
Turnbull can’t campaign on Abbott’s policies, then say he has been commanded to implement his own (whatever they might be). So, unless he breaks with Abbott before the election, he might as hand back the job to someone who really believes in the program he is proposing.
Update 25/3 Turnbull has obviously been stung by Abbott’s attack, and is spinning some minor course adjustments (explicitly dumping some policies from which Abbott had already resiled) as a major break
fn1. The mandate idea is most powerful in a bicameral system with an unelected or highly unrepresentative upper house. In Australia, the unrepresentative aspects of the Senate (equal state representation and long terms) are matched by the spurious lower house majority produced by single-member constituencies. So, senators have just as much a mandate to block legislation they have campaigned against as the government has to push it forward. The Double Dissolution is, of course, the way we can resolve this.