I'll take a guess at what it WONT be!
technology (2008)
how we're judged by our use of language (2008)
2007s speech-making was a weird one, so don't expect that again
offensive language - 2007
2006:
the importance of SAE today
appropriate language use
social changes to language
2005:
public language
Australian English changes to reflect identity
2004:
Inclusion/Exclusion via jargon
texts in context
language as identity
So, my call:
a broad question about language and changing identity - ethnolects haven't appeared in a while
a question about PC language - Kevin Rudd made it too easy this year, especially in the first half of 09
and one curve ball (three questions this year) - a bit out of left field like the speech-making question = maybe stylistic features in written text?