State schools don't have the same reputation as Penn, Cornell, and Tufts.
UC Berkeley, which is a state school, is widely reputed to be among the best research institutions in the world. Of course, we don't have a vet school, but I needed to defend state schools.
As another example, UW-Madison is where computational biology started - if you've done any genomic work you've used FASTA and CLUSTALW and the rest of the GCG/Wisconsin software package. Wisconsin is in the midwest *and* has a vet school! But maybe Wisconsin isn't well known in infectious disease, just like Penn doesn't really do wildlife and maybe Tufts doesn't do much computational biology... There are some universities that are good at pretty much everything, but as sundoggie mentioned reputations are for the most part *very* field-specific.
If research/academics is your goal, I agree that your pedigree matters for getting postdoc and faculty jobs, and to some extent probably funding, for exactly the reason Pennvet stated - opportunities to do easily publishable cutting-edge research and connections to other famous and well-funded labs. But I disagree that private is inherently better than public. And I disagree that the name of the *university* matters much; it's the name of your advisor that should get you places in your field. There is a correlation, of course, between famous and well-funded advisors and famous and well-funded universities.
But unless you're doing a dual-degree program, your ability to get really involved in research while in vet school will be limited. In order to get a faculty job (or government or private research position) you will need to do postdoctoral research at the least (maybe in conjunction with internship/residency). Your postgraduate training probably matters more than the school on your diploma in terms of getting a job and funding. So you should probably go to the vet school where you think you'll get the best *veterinary* education, get good grades, and then go after a big-name postdoc/internship.
Similarly, Angelo, your ability to get really involved in a specialist field such as behavior will be limited in vet school, so again it might be better to get the best general education you can and then go for an internship at a school well known for the specialty. (Penn will not refuse your internship application just because you turned them down for vet school - they probably won't even know.)
But the most important point is that if reputation matters to *you*, then you should go to the school with the best reputation, no question. Otherwise you will spend the rest of your life feeling slightly embarrassed and defensive when pepople ask you where you went to school. This is from personal experience - I never thought reputation mattered to me and I truly think I got a better undergrad education than people I knew at Princeton and Harvard, but now that my graduate class is full of people who went to those schools, damned if I don't feel defensive about my smallish state university...
And regardless of anything else, Ime52007, if you've got the opportunity and the wherewithal, GO TO SYDNEY! I think the fact that it's exotic, and that you had the guts to turn down an acceptance to Penn to go there, will make up for the fact that nobody here knows Sydney's reputation. Hey, you *were* good enough for Penn, right? (Of course there may be practical considerations like licensing hoops to jump through that you should also factor in to the decision...)