Monkey! Good to see you again, and I'm glad to see you're a part of this discussion, since we were both so excited about the 'Walker.
Anyway,
Couldn't someone just analyze a sav file from a ROM? Like... someone who is playing the game on an emulator or flashcart?
And also, you can dump pkm files from an HGSS sav file using the most recent (albeit extremely basic) version of COM's HGSS Pokesav.
I've got over half a box of PokeWalker Pikachu on my retail HGSS cart, I just need to trade them to either DP/Plat or my flashcart HGSS but then I'll have a few that somene could study, but judging from my level of free time (haven't even played the normal game in a WEEK), I doubt I'll be able to get to it soon... someone will beat me to it, if they're ambitious.
But from the one or two I've looked at, I also think the PokeWalker uses an algorithm different from normal Pokemon.
Lastly, doesn't the official site give the frequency or whatever specs on the PokeWalker?
I'll check it out later, running out of time. Gotta catch a train.