The company apparently intends to use hibernation as the standard shutdown method and only fully power down a computer when it is absolutely required, for example due to a configuration change of the OS.
In a patent application filed with the USPTO, Microsoft says that a general startup would only require a partial startup sequence by copying a hibernation file that is created during a shutdown from non-volatile memory, such as an SSD or HDD, to the volatile memory, such as DRAM, of a computer to enable startup times that are comparable to the wakeup times today. Specifically, the patent application explains a startup that covers:
"conditional processing that may include determining whether a hibernation file exists. If so, a further check may be made on whether it is possible that the target state of the computing device could have changed between the time when the hibernation file was created and the time at which the startup command was received. If events that could have caused a change in state are detected, the computing device may perform a full startup sequence."
The idea is that information can be copied from a hibernation file faster much faster than the software would need to load and configure "tens of thousands" of components at startup.