I always read but rarely post, but this is especially relevant so I just have to add my two cents on this topic.
Along with everybody else, my first thought when hearing about this was "Oh, God please let them choose decent hosts." But it actually extends to the entire crew. If they get it right, it could be a really great show. If they don't, it will probably degenerate into the Footy Show / Blokesworld. Kudos to SBS for taking on such a massive challenge to live up to the Top Gear brand.
The weekly Holden vs Ford angle keeps getting mentioned, but give them a chance. A quick scan of the Wikipedia entry on Top Gear reveals that some variant of the Porsche 911 has been mentioned in 38 out of 88 episodes... but I digress... Top Gear has done some very entertaining reviews of some unusual cars: James' Bentley, Hammond's Charger, the GM Hywire (James), AM Lagonda (James). Created interesting angles on some common stuff: Audi A8 London to Edinburgh immediately springs to mind. And stuff that's not Euro-centric: beating a speed camera, remote control cars, towing land-speed record, bus / limo / ice-cream truck jumping. My point being that there's more to Aussie motoring than the V8 supercar PR department would have us believe.
There must be enough depth in Australian motoring to mine at least one decent season without constantly reviewing the latest HSV / FPV. Classic Adelaide Rally, Targa Tasmania, Bolwell, Elfin, Alpha Sports, purple Valiants, 70's Datsuns, Sandmans (without turning into a TV version of "Street Machine"), crushing Land Cruisers with mining trucks (
http://www.liveleak.com/view?i=3d7_1193971489), outback mechanics, track tests of super rare production GT Falcons / Toranas / Monaros, a challenge involving Bathurst, Perth > Adelaide, Melbourne > Sydney, Broome > Cooktown, Darwin > Uluru.
Most car shows are boring because they're too relevant - Top Gear works because it's total fantasy. That's what Aussie TG should be IMHO.