I think the ban has good intentions, but I think people should still be allowed to smoke in areas that are outdoors but still part of the pub/club (ie beer gardens).
I personally don't smoke Australian cigarettes but I think that there should be some pubs/clubs that allow it (like the previous suggestion to have a smoking licence). That way people who don't smoke but don't mind having it around them can socialise with their smoker friends.
These bans may not have much affect on Australian customers, but they definately will with customers that are visiting from overseas. For anyone who has been to Europe, you know that they smoke an awful lot over there, and I'm sure they would be very upset with not being able to smoke inside pubs/clubs, and therefore would not visit them as often.
Without the bans we are pretty lucky with the small amount of smokers anyway! When I visited Austria, every pub I walked into had a thick haze of smoke; and probably about 90% of the people smoked - in fact there are so many smokers there that by the end of the trip I had turned from someone completely disgusted by cigarettes, to a social smoker. (Although their cigarettes have less "bad stuff" in them, hence why I don't smoke Australian ones.)