I don't think they mean Path as in Pathfinding, but rather drawing a set path for objects to follow. A Pathfinding plugin like you're describing would be something totally different.
Anyway, if it's at all possible I think the IDE side of things should link the waypoints for you automatically. It would make the plugin much more intuitive for new users. One would sort of expect it to work that way, after all. Having to link your waypoints using events isn't very user friendly.
You could use the same sort of method that making custom masks for physics objects does, by having an "edit path" link in the properties.
Also, support for two kinds of paths would be nice... Loop (which would work exactly like the mask editor for physics, where it auto-closes a shape) and Line, which would basically make an open line.
As for movement along the two kinds of paths, Loop would default to tracing the path in one direction repeatedly and Line would default to a ping-pong sort of behavior back and forth from end to end. Again, I'm just thinking of ease of use here, as these are pretty much the most basic sorts of things that people are looking to use Path movement for.
I think a Path movement should also have an option to "Orient to Path," like Flash does. As in, the object will point along the path in the direction it's moving.
Oh, and some Exact and Interpolated settings. Exact would follow the path exactly as you drew it, with sharp corners. And Interpolated would make nice beziers through the corners.
Just throwing out ideas here, take them for what you will