The last space shuttle, Atlantis will possibly blast off for the final time on the early morning of this Saturday Australian time (11:30 am Friday, US time). Bad weather may delay the launch though.
Still, whenever the shuttle launches this will be the last time we can see the ISS and the Space Shuttle in the sky together. From Australia, ISS overflights will be in the morning for the next 10 days, so you will have to get up around 6:00 am local time (for exact times at your location see Heavens Above). Depending on the actual launch time, we may see the ISS and shuttle widely separated on the Saturday morning, or close together on Sunday morning. Keep checking Heavens Above for actual times he two can be seen.
Cloud cover predictions can be found at SkippySky.