So, what is there to watch on digital television? All of the free-to-air networks (ABC, Seven, Nine, Ten and SBS) have a digital version of their analogue offerings. They also have extra channels, which can be varied by the channels for special events. For example, Seven will have a digital channel exclusively for the Olympics.
There's a program guide showing what's on widescreen and high-definition (HD) for each day. In summary, a lot of the popular stuff, such as news, sport and high-rating UK and USA serials are shown in wide-screen. A few regular programs, and a few films are in HD, but that includes nothing that I normally watch. They don't broadcast in HD in the UK, so programs from there are never HD.
There is very little extra programming content on digital television. The ABC has one digital radio station, SBS has a world news channel (continuous unsubtitled foreign news bulletins) and a weather and news summary channel, consisting of maps and text with classical music. The ABC had two additional televison channels until 2003, when their (overall) funding was cut by the federal government.
I am not in a position to comment on the quality of HD broadcasts, because my monitor has a resolution of 1024x768, which is far below the (interlaced) HD resolution of 1920x1080. However, I am able to comment on the reception. Using my gimcrack antenna I can get all channels clearly (with 70-80% signal strength), whereas with my analogue VCR sitting next to my PC with the same antenna I can only receive 3 of the 5 channels with clarity.
Watching widescreen programming on a normal old (4:3) television (via tv-out from my PC) is not a pleasant experience. I find that I need to use pan and scan to fill up the whole screen, whilst losing the sides of the picture.
So, I can see that digital television is the future, but that there is so little content at the moment that it's not worth expending any money on it yet. I certainly would not consider getting a standard definition set-top box for my main television. If I could pay $50 extra to have a digital decoder built-in to the tv then I'd go for that.
If the government wants to encourage people to go digital so that they can release analogue radio spectrum for other uses, then they'll have to encourage better content for the digital channels.
SUMMARY
If you're buying a tv tuner for you computer, go digital.
If you're buying or already have a wide screen tv, go digital.
Everyone else should ignore it until there's better content.