If, like certain people I know, you think the HTC is the second coming of Christ in phone form (he knows who I'm talking about), you might be happy to know that according to the Canadian HTC site, the Hero will be running on the 850/2100MHz spectrum for Telstra.
It seems that a few versions of the phone will be available: a 900/2100MHz version for the EU, and 800/1900MHz version for the US and an 850/2100MHz version for Telstra. It's the only carrier specifically named on the site.
Considering how chummy the Big T is with HTC in regards to Winmo phones, this wouldn't be a big surprise. Also, even though it's pureley coincidental, when HTC showed me the handset a few months ago it had a Telstra SIM card in it.
The good news is that even if the Hero is a Telstra-exclusive in Australia, the fact there are different versions for different markets means you can probably get an OS model for different networks here in Australia, as the EU version matches the networks used by Optus and Vodafone.
Of course, this is all purely speculation until HTC drops the official word, but it's looking pretty convincing...