For anyone who is interested, here is what I am hearing.
The Creator's edition of Windows 10 is coming out April 11th. Around the same time, the Surface 5 or some other product (it may be a Surface Book that gets announced), will be announced but not necessarily available. \
What I am hearing is 4K video, Thunderbolt, Kaby Lake processor and long battery life, which is why I am thinking it will be a surface pro announcement with the Creator's edition and not the Surface book 5. I think they have a battery issue to contend with for the Surface 5, you wont have 4K video, a U series Kaby Lake and long battery life, that would indeed be something to speak about but I doubt it would happen, that is why I am assuming it will be a Surface Book announcement and not the surface pro 5 we are all anticipating.
I do expect to hear a surface pro 5 announcement, maybe at the same time, but I suspect the battery life will be measured in minutes, the cost will require a mortgage and the weight will be measured in kilograms rather than ounces if they stuff all of that feature list into the small footprint of a surface pro 5. With what is circulating, that is why I am suspecting a surface but not the tablet footprint in April (I of course could be wrong).
All that being said, there is some significant engineering to take place to have 4K video, all day battery life, Kaby Lake U series processor and the footprint of a Surface Pro 4. Unless they have some significant improvements into batteries, I find this hard to fathom.