This is becoming a frequent question on these forums, and will increase in the foreseeable future with the bottlenecking of training positions in Australia. While the popular topic in this forum is usually in to regards internship positions, this is by no means an end point for many graduates. Many graduates have an intention to specialize and gaining entry to a specialty training college in Australia is infinitely more difficult than securing a house officer position (vocational versus prevocaitonal training, respectively). Not only are there far fewer positions relative to the number of applicants (even worse than the ratio in the US), there is the added element of applicant selection criteria that drives the competitiveness beyond what many are willing to undergo. For instance, while I was working as a house officer and medical student in Australia I spoke with many applicants that waited years to get in to a training program. This highlights a point I have made on this forum before - in contrast to applications in the US, having more "clinical" years under your belt (i.e. prevocational training) looks MUCH better to the AMC-accredited specialty college selection committee; however, this is almost universally seen as a red flag in America.
Apologies for the protracted preface. To answer the OP's question, absolutely and unequivocally yes.
There are many posts in this forum from people who have successfully made this transition. I recently went through the 2014 Match, having graduated from the UQ four-year Australian MBBS program. I diligently studied for the USMLE (Steps 1 and 2 CK are the ones that matter for your application) and I took the opportunity during medical school to publish, present, and get some medical research on my CV.
Not only is this particular scenario not impossible, it was quite smooth. If you don't have any visa issues, then you are set. There are a lot of assumptions about the process of IMGs going through the Match, but I'll reiterate what has been said many times over in this forum. Your success in the Match will depend (mostly) on applicant-dependent factors (USMLE scores, publications, rotations, LoRs, etc.), rather than applicant-independent factors (location of medical school, citizenship). With that being said, this is not definitive. Having graduated from Australia will put you at a significant advantage, as opposed to earning your degree from a non-English-speaking country and/or medical school curriculum. In fact, many of my interviewers and program directors I spoke with were very excited to meet with me and the fact that I graduated from Australia was an interesting topic of conversation for almost all of my interviewers (there was a slight disappointment for many when they heard my American accent though).
In my experience, there was no difference between myself and the domestic applicants. However, this will greatly depend on the specialty you apply to, the places you interview at, and your interpersonal skills. I received 17 interview offers, accepted 9, and matched at my #1 choice.
I can't stress this enough:
1) Score high on Step 1 and Step 2 CK of the USMLE (finish CS for the ECFMG certificate); there is no particular order these need to be taken after you finish Year 2 of an MBBS/MD program.
2) Get GREAT letters of recommendations (3 or 4); highly preferred they are in the specialty you are applying.
3) Rotations in the field to which you are applying
4) Publications and presentations
5) Good interview skills
As a side note, if you wish to return to Australia in the future as a board certified American attending (consultant), there are Australian immigration pathways set up to facilitate this, but will depend on the requirements of your specialty college. However, it will be much easier to go from America to Australia (you won't need the internship if you're an attending) than going from Australia to America (as a consultant). The United States, in general, does not recognize specialty training from anywhere besides the US and Canada; there are exceptions to this however (e.g. reciprocity agreements with Family Medicine).
