My theory is that it's related to what I've come to call Geranid's Certainty Principle. Namely, that measuring an attribute of a spren (and recording that measurement) fixes said attribute for as long as the record stands. Kaladin serves as caliper and record for Syl. Remember when she left him, and almost lost herself? Somehow, he is measuring her, and she evolves along with his "record" of her attributes.
I'm surprised no one has mentioned the blatantly obvious parallel to Heisenberg's Uncertainty Principle, from modern Quantum Mechanics.
Basically the idea is that a particle can be in any one of eight different states UNLESS you actually measure it - then it is DEFINITELY in one state. But until it's measured, it can be in any one of those eight states (or perhaps even eight at once?).
There are already working computers that take advantage of this theory. Things that shouldn't work... and yet they do.
-e-
I got Heisenberg mixed up with Schroedinger
Why stick with just eight states? For unbound systems, there is an infinite continuum of states a particle can be in, and which it will be in is somewhat undetermined until a measurement is actually made!
Heck, even for bound states, there are usually a countably infinite number of states. (And even then, the discrete energies is really only an approximation. Everything you learn about physics is a progressively less flagrant lie until you get past the graduate level courses into the real literature.)
However, the parallel to the Uncertainty principle is quite obvious, that is for sure! Not sure how it's going to play out, but I believe Brandon has said it's pretty important.
As for working computers... technically we have them. If you're willing to pay a few million bucks to factorize 15, you can indeed have a quantum computer. Practical quantum computers? No.