Dave - Can count on you to read the blog details earlier than everyone else, and totally get what we're doing. Smart post.
re: user replacement, we have a couple thoughts -
For most consumers, they don't want to deal with moving parts around, so we stepped up the alternate keycap printing. That way we take care of it on their initial config and it's ready to go. If they ever need service, we can swap out KeyBlade subassemblies for them.
For technology hackers, we're thinking to make a modder kit (blank keycaps, spare butterflies, and an installer tool) so they could play around with different arrangements and experiment.
We may also offer individual blade assemblies a la carte for folks who want to change layouts frequently.
Let us know what you think.