I think it's pretty obvious that you guys have jumped the gun, here. While it's true that the code allows for these Pokemon to learn Volt Tackle, that doesn't mean it's an egg move at all.
Chances are good that it's just a tutor move to be introduced in Platinum, which will not be possible to pass on via breeding at all, as it wouldn't be a level-up move OR an egg move.
Like Softboiled Clefable.
EDIT: What would be a good idea, though, would be for someone to see if Gunk Shot Crogunk or Seed Bomb Pachirisu are in the code somehow. However, if they aren't, then chances are good that Game Freak is adding a lot of new code to Platinum. This theory would be backed up by the fact that Nintendo is only allowing Platinum in all future events... and excluding Diamond & Pearl.
Unfortunately, there is always the chance that nothing will ever come of Volt Tackle at all... left as unused data.