There is no difference, it is still the same material using textures from the content browser. The only difference is you can set a TextureSample node to use a Wrap or Clamp method (depends on the texture) of sharing instead of using the sampler for one texture only. You can visualize this as a kind of (sort of) texture-atlas that is built by the engine automatically, it does not affect the artists workflow at all.
Here is some more info:
Unreal Engine 4.6 Preview! - Announcements - Epic Developer Community Forums!
But the actual documentation won’t be out until 4.6 is released. 