"Legacy Free" has been discussed for years. It's not going to happen until a replacement for the floppy drive is available, which is truly plug and play and provides all the same capabilities and can work with a simple boot disk.
EFI doesn't sound all that revolutionary, just a "next step" in how to provide the functions of the BIOS as well as giving it newer features. A long-delayed next step of course. But it started in 2003. Doesn't sound like a project "steadily gathering momentum" to me.
People still have enough problems with USB to make removing PS/2, serial, parallel ports from all systems just a scream for more tech support calls.
SerialATA and PCI Express of course will be able to come into use fairly quickly now that it's starting to appear. However SATA also won't be very momentous until it's integrated into chipsets, which after that will mean being able to completely avoid parallel ATA since SATA in the chipset should be software compatible to the OS (no more needing to plug drives into the chipset controllers in order to run utilities). PCI Express may have a bumpy road for a while, considering the PCI-X competition that may happen. Certainly hope we don't end up with an either/or situation in our device choices.
Of course, OEM systems will be the place that total legacy-free begins, since they can build a system that works completely and the user won't have to worry about it.