If certain people in the know are to believed (Paul Thurrot, specifically) the next generation of Microsoft's Surface Pro will bring only small, incremental updates. Now that in itself isn't an issue, the Surface Pro has matured quite nicely in its last two iterations and small upgrades to processor, memory and disk are entirely acceptable.
What isn't acceptable is the suggestion Microsoft may not be including USB-C in the Surface Pro 5.
Wanting to retain the existing docking connector is a good thing, don't get me wrong. It allows customers to leverage their existing accessories with a new product, something which does wonders for customer loyalty.
However, USB-C is the connection of the future, providing all of the power supply, docking and expansion capabilities a modern laptop needs. In order to stay inline with the competition Microsoft would need to pack at least one into the Surface Pro 5, allowing users to choose between the standard Dock Connector charger or a more portable USB-C one for travelling.
Suggestions that Microsoft might not do this to retain the USB-A port aren't believable. There's a Mini DisplayPort connection on the SP4 which would could be replaced by a USB-C port and provide display out, connectivity and power all from one socket.
Even if it weren't the case and adding USB-C could only happen at the expense of a USB-A port, it would be a fair price to pay. The Surface Pro should be about looking forward not looking back.