There are stats here but I believe they combine ETH and ETC. Where can I see the distribution split in full nodes between the two forks?
The Ethereum Chain State page has some side-by-side metrics regarding each chain.
Pertinent observations as of 2nd August 2016:
- Block times for both chains have almost reached parity;
- Hash power for the non-fork (ETC) chain is ~27% that of the forked (ETH) chain;
- Correspondingly, the difficulty for the ETC chain is ~27% of the ETH chain.
Note that while hash power and difficulty give an indication of activity on each chain, it can't be reliably used to quantify the number of mining nodes.
With ETC being so new, it may take a few weeks for all of the good tools to emerge that will help us observe the sort of data you are asking for.
In the meantime, two comments:
1) this is, of course, quite dynamic. Nodes on either blockchain can and do change frequently. So be aware that there is no clean static answer for you.
2) two sites that both show partial lists of the mining nodes are:
The reason they are partial is they only show nodes that have volunteered to have their data published to those sites.
I'll monitor and add to this post if I can find a better site for these data.