Howard will always do better in more conservative/rural areas.
Costello should work better in the mortgage belt, which I think the election will be fought - if interest rates go up further... Many are just outside marginal status... but a swing wouldn't need to be huge or uniform.
Lab needs to win federal seats in QLD DESPERATELY...
Labor should focus on getting back the two seats they lost in Tasmania. It's a relatively cheap eway to gain two seats; it's much more expensive for an ad campaign in any other state, and the ground campaign would be about the same in time and cost. Also, Solomon in the NT which has the same benefits.
So that's three of the necessary 15 or so seats
The only likely place for many of those 15 seats is Queensland-many of the South Australian marginals are already ALP IIRC.