The Labor government of PM Kevin Rudd appears to have secured the votes of enough opposition Liberal Senators–the government lacks a majority in the Senate–to assure passage of its emissions trading scheme (ETS) bill.
The Liberals are in the midst of a leadership crisis over the issue. The price of support from within the opposition has included offering seven billion dollars in assistance to the coal and electricity industries.
Update: The Liberals have a new leader, Tony Abbot, and the voting was pretty exciting, with a 42-41 final round of voting. Abbot staked out the clearest anti-ETS position, so there is presumably still more excitement to come in the Liberal caucus.
Update II: As noted in comments, the ETS bill failed, because too few Liberal Senators crossed over. And so now there is talk of a double dissolution (new elections for not only the House but also all of the Senate. This is indeed interesting!