Looking across the Australian government, there are now at least several different platforms used to deliver successful blogs.
For example the ABS's Statistically speaking blog uses Blogger (as I do for my blog), a free service from Google, whereas DEEWR's Training.gov.au project blog, the Austrade blog, the Australian War Memorial's blog, the Victorian Public Service Continual Improvement Network and the Sydney Observatory blog use Wordpress, also available for free, or in a paid version.
A couple of others I can't determine the system used - if anyone can tell me which system their blogs are using I'd appreciate it (including Defence, DBCDE and Mosman Library).
Considering the platforms I can identify, there's some clear benefits for agencies and for their audiences,
- The platforms are familiar - they are in common use across the internet (therefore offer familiar controls and functions)
- They are simple for government business areas to set-up and operate with little or no ICT involvement required
- They are hosted through third parties, rather than requiring government investments in infrastructure and bandwidth
- They provide the capacity to plug in RSS, photos, videos, analytics and various other tools quickly and easily - again with little or no ICT overhead
- They offer configurable moderation of comments
- They support single or multiple-author capabilities
In my view these are all useful in getting government blogs up and running quickly with a minimum of cost or stress. They also allow the primary focus of blogging activity to be on managing content and responses rather than on managing technology and development.
If you are looking further afield at the options for blogs, Elance has published a good article covering some of the most common blogging platforms, appropriately titled The Best Technology Platforms for Bloggers.