That's great Iain!

Right now it looks like most people from low risk countries get theirs within 3 months or a little bit more. It all depends on how complete your application is and what the circumstances are. I dare say that yours may take a slight bit longer than the average if you have to do a medical waiver like you said--im not sure how that works, it might not affect processing at all. Also, a lot of embassies are currently swamped with applications--if you can wait till jan/feb to apply, things might slow down a bit by then, but then again maybe the "swamping" has less to do with the holidays and more about the recession.... you can call your local immigration hotline and they can give you an estimated time.

What might be a good idea though is be prepared at your imigration medical (you have to get it done by an aussie panel doctor) by bringing all the right info from your other doctors, eg how your diabetes, epilepsy and hypertention are well controlled. I don't know how the immi doctor would use that in their report, but it couldnt hurt to have it all with you to prove that yes, you have some health problems, but no you will not be making a significant impact on the medicare system. I and most people wouldn't have to bring extra documents, but i would if i were you just to be on the safe side.

Very happy for you that you got some good information--tons of people have gone defacto on this board so have a poke around, there is tons of info and experiences.

Good luck!