Disclaimer: While I am an Australian law student, I've only read the summary of the decision, (c'mon, it's 200 pages), nor have I studied IP Law.

However, I do have a year of Law school behind me, so:

  - Australian law makes a distinction between findings of fact (i.e. John stabbed Mary) and findings of law (i.e. law x says stabbing is illegal). Findings of law can be appealed (you can argue the judge misinterpreted the law), but it's *much* harder to appeal a finding of fact. AIUI, there aren't many findings of fact in this case: the Justice found that Malone was a credible witness as a matter of fact, but the rulings on which the case was founded (i.e. that BitTorrent is the means of infringement, as opposed to the internet) are all findings of law.
  * tl;dr => Most of the ruling could be overturned on appeal.

  - The case was decided by a single judge of the Federal Court. That means that, IIRC, it will be appealed to the full court of the Federal Court (3+ judges). From that, it could be appealed to the High Court. (The highest court in Australia; equivalent to the Supreme Court in the US)
  * tl;dr => The appeal may not be the last, there could be another.

  - I'm not going to venture an opinion on the outcome of the appeal; I don't know enough. I also haven't been able to find AFACT's grounds of appeal; if I can I might be able to shed some more light on the possible success.
  * tl;dr => Who knows what will happen?

  - Ultimately, AFACT and their lobbyists will likely convince the politicians to change the law, whatever the outcome. This will probably suck - Aussie Communications Ministers traditionally do an average to poor job regardless of political persuasion. (examples include: mandatory filtering, "World's Greatest Luddite")
  * tl;dr => What ever happens, we're probably screwed because of politics.