I finally figured out how to polish the general set of diceless rules that I've been meddling with for a while (basically the rules set that Nano-Victorian Future is based off of).
You can get a general feel for the rules here.
Basically, it uses an Amber-ish diceless conflict resolution - whoever has more points wins. Characters are based on three types of properties: attributes, powers and knacks. Attributes are qualities that everyone has, and the primary focuses of conflict. Powers are qualities that some have, and some do not. Knacks are features unique to the character. Every character should also have a motivation, a couple words that sum up the main narrative drive for the character.
Exactly what the attributes, powers and knacks are is setting dependant.
While I haven't made it explicit in NVF, I've got a loose system for using powers and knacks in conflicts. Depending on how broadly usable a feature is, I either just add it in for the conflict, or double or (rarely) triple it. Moving forward I think it will be more clear if I let a player know up front if a given feature is straight-up, two-fold or three-fold. For example, a cloak of invisibility does only one thing, where "super-senses" is more broad, so the former would be two-fold and the latter straight-up. You would need to have more than twice the points to see past the invisibility cloak with your super senses.
In a fantasy setting, this would be pretty important if powers included being highly skilled at something (like fencing, say).
Finally, I've noodled before about the "Princess Bride problem" - how do you deal with Wesley and Inigo game-wise, letting Wesley win when they fence even though Inigo does nothing but fence? Previously, I figured that the solution was "fate points" in service of Motivation, but worried that the game would devolve into the players trying to game the fate point system.
My new idea is to simply not tell the player how many points they have. That introduces uncertianty into conflicts without overly eroding a PC's competancy. If you try to use a fate point and you're out, the action will either fail, or the player takes "damage" in one way or another.
It's probably a big PITA for the GM, so I'll have to work out some way to track this for myself during play, but I think it's worth a shot. I won't change the existing game I have running now, but I'll make the tweaks to any games I start up in the future, including convention games.