Hello!
I forget to put my visa processing update on this thread (from way back on page 450!)
My girlfriend (Australian) and I (British, London born and bred) were together 3 years and 6 months on date of application. I had been in Australia since 2006. Went back to the UK to apply as waiting times are a lot shorter.
We lived together for 2 years 6 months before that in Sydney. I was on a 457 business sponsored visa and a 416 Working Holiday Visa (x2, I did fruit picking for the extra year in Bundaberg!) before that.
Applied: 07/01/2013
Location: Australia House, London
Payment Taken: 09/01/2013
Case Officer Assigned: 21/01/2013
Police Check: 28/03/2013 (United Kingdom Police Check and Australian Federal Police Check)
Medical: 30/04/2013
Visa 100 (Permanent Residency) Granted: 31/05/2013
Total Time: four months, three weeks
Advice
Maintain contact with your case officer. Be nice, we chatted about the weather, good pubs in London and life in Sydney (my CO was female)
Don't front load your application. It gets stuck in piles of other applications. Get your police checks and medicals in separately. Ask your case officer to confirm they received it.
Don't panic about not hearing anything.