don't worry people, the mails don't mean anything. They are used to try and change (or not change) your mind about your preference. They usually mail to those students who put their unis either as a 1st, 2nd or 3rd preference. So everybody will probably, eventually get yours soon.
Last year I got one from UNSW and one from USyd... obvious UNSW is hoping that I keep UNSW as my first preference. USyd, since I put it down as a 2nd preference, sent me all these keyring crap and booklet about how wonderful USyd is blah blah blah..to make me change my 1st preference to USyd.