I think there are immediate ML applications in medicine in addition to radiology.

Drug discovery, any kind of imaging (retinopathy, neuroimaging, ultrasound etc).

I think the reason DeepMind are also doing a non-AI related project with NHS is because it's a quick win (current hospital IT is horrible) and they are in some ways trading it in exchange for access to lots of medical image data.

I agree there need to be more public anonymised medical datasets, so research results can be benchmarked against a common metric.