Is it the same thing as the copenhagen interpretation, what's different about it?
Copenhagen has a blemish - namely how does a theory that assumes the existence of a classical world observations appear in explain that world. Neo Copenhagen is an interpretation that fixes that up - the one I know being Consistent Histories:
It does it by doing away with observations and using the concept of history - which is a series of projection operators. QM in that interpretation is the stochastic theory of histories.
There may be others as well, but its the one I am familiar with.
Lubos also explains it pretty well:
Well, it seems they still add new flavors to the Copenhagen interpretations. Overexaggerating it a bit: There are as many Copenhagen interpretations as quantum physicists subscribing to that interpretations :-).
That's true as well - and you are only exaggerating a bit.
Most however have observations as the basic primitive and the state that determines the probabilities of the observation as subjective knowledge similar to the Bayesian view of probabilities.
In fact that jogs my memory - Quantum Bayesian can be considered a neo-Copenhagen interpretation:
But as far as I can see its really just being explicit about the interpretation of probability used - so I would call it a more careful version of Copenhagen rather than an actual change.
It would be helpful if you would tell us the context in which you encountered the phrase. I expect that you found it in the Leifer paper ("Is the quantum state real? A review of ψ-ontology theorems") to which you were referred earlier? If so, Leifer provides a definition, and if you have follow-up questions based on this definition you will have to be more precise about which parts you need help with.
Please don't just repeat your question without doing some studying first.
Separate names with a comma.