Feels like we've been waiting for ever but finally my wife's eligibility email is here :-) we can now submit our 457 visa.
For anyone interested in timescales, all documentation was delivered to AHPRA Adelaide by the beginning of November 2012, everything must have been ok with it as nothing was queried. They asked for the letter of good standing from the UK NMC, this was posted by NMC on 7th February. Eligibility received today.
Almost 4 months in total, not quite what we expected so it's been a stressful wait!