Will the government hold onto the Senate?

Up until yesterday, I had pretty much assumed that the Coalition would automatically lose control of the Senate after this election and after the new Senate comes into affect on 1 July 2008. Someone pointed out to me that given the 2001 results this would require Labor to do extraordinarily well in two states ie get the 54% of the vote required to win 4 senate positions. I must check this out next week but if true it would make the IR debate very interesting in the next Parliament if Rudd wins the lower house but not the upper house. Or would it just give him an excuse to modify his pledge to throw out WorkChoices lock stock and barrell. Hhhmm.