According to CNET's iPad Pro review, Apple's just-released tablet is capable of supporting USB 3.0 transfer speeds via its Lightning connector. The report, which corroborates a finding by iFixit, and was later brought to our attention by MacRumors' Juli Clover, is notable for a few reasons.
First, it would make the iPad Pro the first and only device that Apple makes (that's not a Mac) to support USB 3.0 transfer speeds. Secondly, it means that copying large 4K video files to the device will be much more feasible.