I'm a West Australian. It's occasionally brought up from time to time but noone seriously proposes it. In more recent times a WA First political party was registered for the last Federal election and it barely gathered a significant turn out. The State Minister for Mines, Norman Moore, is an outspoken secessionist who often 'hints' at secession - but the Premier pretty quickly comes out to officially dispel any suggestion there is a serious consideration of it.
We have seen a lot of argy bargy over the GST receipts to WA recently, each review it seems WA will be getting less and less and consequently the Premier raises this as an issue. WA has also announced it would join the mining companies legal action against the Commonwealth over the Mining Tax as they (WA) believe it is unconstitutional. But this is mostly partisan political in nature. Premier Barnett is enjoying making life more difficult for a very unpopular Federal Government and it is reflected in his high opinion poll figures. If it were a Liberal Government in Canberra, or conversely a Labor Government in Perth, I dare say the whole thing would die down.
In regards to the 1933 referendum, if memory serves me right it was the Conservative Coalition that pushed hard for the referendum. Even though the referendum was successful, the Coalition lost that election very badly. Labor had campaigned against it, but when they won Government felt honor bound to 'do their best' so to speak. They sent a delegation to London and petitioned the British Parliament to once more become a crown colony and secede from the Australian Commonwealth. After some deliberation London decided it could not, legally, intervene in what was a sovereign matter for the Commonwealth of Australia.
If you could somehow get that Conservative Government to win the election which drove them to oblivion, it is possible they may push hard enough to secede. Legally I don't think it's possible, but if there is an outright declaration of independence and a refusal to pay Commonwealth duties I'm not sure what would happen. Civil War would seem highly unlikely. I suppose it would be a battle of wills. Would the Commonwealth or the State cave in first?
Either way if you want an independent WA the 1933 referendum is your best bet IMHO. There has been no other statistically significant support on the issue since then.
P.S: Just as a matter of interest the way the Constitution is worded the Commonwealth and the States each have their own Monarch, represented by the Governor-General or Governor respectively. This was an issue raised during the republican debates at which some States (WA included) indicated they would like to remain a constitutional monarchy even if Commonwealth became a republic. There remains to this day considerable debate amongst constitutional lawyers about how this particular issue would be resolved. So theoretically there could be a potential legal remedy to secede but I highly doubt it.