Apparently a lot of people want to know things about BeagleBone boot time...
Let me know if this is covering it or if you'd like more info. Most of my work is with CLFS and Debian.
I'm seeing about 8.5 seconds from kernel start to login prompt with a rather pared down Debian Sqeueze armel configuration and Linux 3.1. Add about two seconds for SPL, u-boot, and kernel decompression. Then add on the boot delay countdown (3 seconds in my case). That gets us to about 13.5 seconds to boot.
Let's be conservative and say 15 seconds. Completely respectable. Not a 1 second boot, but that's not my goal, anything under a minute is pretty good in my book.
To give you a sense of what I'm starting at boot time for services, here's some output: