Later this year there are likely to be significant changes to the Brisbane town plan brought into effect. An interesting revision will be the change in minimum lot size from 405 to 300 square meters, this will mean that a standard residential block of 600 square meters in a low density zoning with a 15 meter frontage will be a candidate for subdivision into two lots.
The push to higher density for a growing population means that you somehow need to address the most significant cost of bringing on new stock, this cost is the land itself. More information about block size minimums and town planning changes at the Brisbane City Draft Plan 2012 site
The change in minimum lot sizes is like most change, a massive opportunity for those who see the potential and are able to act on it.