Here is an interesting problem, if you want to call it that, which Microsoft had to address when building Windows 8. We all want faster boot times and Windows 8 delivers on the front. The problem is that the boot times are so quick that when you need to enter the setup menu, by pressing F2/F8 during boot, there is literally no time to do it.
So, what did Microsoft do? Surely they are not going to artificially slow down the boot time to compensate for this, so they added a few new features to the OS to make it easier to access these menus.
In a machine with an SSD installed, you can boot up a machine in 7 seconds and the time to boot will likely get shorter as hardware improves over Windows 8 lifecycle. In a test machine at Microsoft with an SSD and UEFI system, the time window to hit F8 is 200 miliseconds, good luck hitting that with any bit of reliability.
In the scenario where you can not boot to Windows, Windows 8 will automatically enter automatic failover behavior which is determined by an algorithm that establishes a baseline over several boots. This should help appease those who have ever had what appears to be a successful boot but only to have the system hang due to a bad driver.
Microsoft penned up another dissertation worthy post on the Windows 8 blog that goes in to great detail about the issue, how they worked around it and the new features coming with Windows 8 that addresses all of these issues. The video below does a great job of taking that post and turning it into a palatable bite seized chunk but it does not go in to the detail of the Windows 8 post.
The good news is that Microsoft offers many ways to easily get to the boot menu options for when it is needed. For the most part, the average consumer will never need these features and the fast boot of Windows 8 will be a welcomed upgrade from Windows 7. But for those of us who need to get under the hood occasionally, Microsoft has you covered.