Good news, everyone! According to some real-world testing by Lifehacker, Windows 7 is booting 20% faster than Vista. On an identical system, Vista Ultimate took 37 seconds to boot from operating system selection screen to the login screen. Meanwhile, Windows 7 took just 27 seconds...the exact same time as Windows XP.
But actually, since Windows 7 still isn't entirely optimised, we could expect to see even faster loading times than XP. Maybe 26 seconds or 25 seconds. Maybe 24 seconds or 23 seconds. Maybe...you get the point.
In fact, Microsoft has achieved internal boot times of just 15 seconds. So getting even lower is a pretty distinct possibility.