yep, that's where i got the idea to begin with.. i liked the concept, but wanted something more user-friendly :)
There is no way (that I know of) to actually create and display a bootmenu, but you can get into the U-Boot environment and execute a 'run boot_sd' or 'run boot_nfs' with the way I have it configured. If you could find a method to stop autoboot and run a few echo commands after initialization I suppose it would work as a makeshift bootmenu but I have not seen such functionality in the documentation. However you will probably want to leave autoboot enabled and a default bootcmd set, otherwise you will need the console connected everytime the plug boots.
I was afraid of that. I notice there's a pretty big banner when u-boot starts, and i'm guessing one can probably edit that banner, since we are creating a new u-boot image as part of the kernel installation. It wouldn't be quite as 'dynamic' as one would like, but i would think it would allow autoboot to be enabled, as well as provide the appropriate instructions.
Anyone familliar enough with u-boot to know where that lives? I'll get out the hex-editor if i have to, but would prefer not to :)