>Classification is only one problem in machine vision. As in, not even 10% of the whole.

Classification is extremely representative of the challenge of machine vision. Good classifiers can often be adapted to do localization and other tasks, e.g. by scanning the image to see what parts contain an object.

The Imagenet Large Scale Visual Recognition Challenge has 1000 classes which you can browse here: http://image-net.org/challenges/LSVRC/2015/browse-synsets I forgot that Imagenet itself has more classes than that. But it's best known for this specific competition of 1000 classes, and everyone uses that as a benchmark.

>freaking AlexNet was not a fraking cat recogniser.

I never said it was... It's actually a dog recognizer mostly : )