For the first time, there exists the possibility for a software agent to roam the internet with it's own wallet.
Using Bitcoin - It could purchase the resources it needs to survive (hosting/cpu/memory) and sell services to other agents or to humans.
To be truly effective and survive 'out there on the net' long term, you'd probably need some basic AI and the ability to move itself between service providers occasionally - but even a relatively dumb agent might survive for a while.
What initial goals such agents might be given is anyone's guess. Funneling back to the programmer any profit over and above what the agent needs to survive would be the obvious case, and of course many such agents might be considered 'nefarious' depending on how they're programmed to achieve that goal. Other agents might be designed to provide free services or act in a way to support some piece of internet infrastructure.
A really interesting development would be if someone released a bunch of these things with a Genetic Algorithm component so that they 'bred' with each other in order to find the best balance between profit and durability.
Anyone know of examples of people discussing or working on this?
Well, 4 years on this still hasn't really materialized - but I think now, with a lot of focus going over to "blockchain" as opposed to digital currencies standalone - and with progress is smart property and especially smart contracts, DACs could finally begin to take off. Hearn's 2013 talk about TradeNet and driverless cars which own them self could not have forseen the explosive growth of Uber and what a DAC'd Uber controlling a fleet of driverless cars could be just that..