UTR you beat me to it, nailed it, the aviation market here is simply too small to make a service like that viable.
If you want to experience general aviation in all its glory, you do need to go to the US.
I'm getting pretty close these days to what's possible here -- in a lightie with no place for an actual radar -- with my Garmin 530/WX-500 Stormscope combo plus a NextG-connected tablet PC (Fujitsu P1620).
On a recent flight to the Rock, I was amazed how far I had (even 3.5G) network coverage (Nokia E51 atm without external antenna, holding the phone up was sometimes required), basically it drops off a few hundred miles east of Birdsville, and then you get it back approaching the Rock..
The update cycles of the BoM site can indeed be a problem, the sat loops can be up to an hour old sometimes, but generally you get the picture, and together with the area and terminal forecasts, can get a pretty complete picture of prevailing and developing weather.
In this context, I can recommend 'Weather Flying' by Robert Buck, although quite repetitive in parts, it does give very good advice on a lot of, ehem, weather flying
Enjoy
