Thanks for the response and the paper link. I'm confident that the connectomics project does use cross-validation. I'm just wondering, is the 95+% accuracy you mentioned on the training data or the test data?
It is from cross validation. The training data is for building their procedure, and then the procedure is applied to testing data that was kept separate from the data used to train.
Here's a great article by Paul Allen about why the singularity won't happen anytime soon. Basically a lot of the things we do are just not amenable to awesome looking exponential graphs.