This does mean that between boots, the system isn’t re-initialized (because it’s not typically needed). If you do make a hardware or system change that requires a system initialization, the system typically handles this for you automatically.
However, you can also force a full shutdown, and therefore full system initialization at next start, by adding the /full switch to the shutdown.exe command. For example, entering
shutdown /s /full /t 0
performs a full shutdown (not hibernating the kernel session) with no time delay.
For more information on the boot changes in Windows 8 see the MSDN blog about boot times. It’s a great read.