Question submitted:
"Is a card moving from one zone to another considered to be 'entering' the zone? The rules specify cards 'moving' between zones and cards 'entering play', but do not specify that 'entering a zone' and 'moving' between zones are the same thing."
Nate's reply:
"When a card moves from one zone to another, it does enter the new zone.
Since it was already in play (in the previous zone), it is not consider to enter play."
So the general consensus was correct, but it's still nice to have the specific defined.