Based on a now-closed thread, it appears that the plan is set ZG back to a single-cast troop in 4.2. I think this is a missed opportunity.
ZG need not be the single most powerful item in the game, but it should be at least worth something. People would try harder to get it if it were something worth having. The player base would come up with creative ways to put ZG in a deck, other players would see those decks and want ZG, and the economy would drive the price of ZG higher.
As a single-cast troop, it’s a worthless, shiny trophy. Only the most dedicated collectors will work hard to get it.
Devs, I think you would get more participation (read: more money) if you left ZG alone. ZG is currently a lump of coal. It doesn’t have to be gold, but it should at least be a carrot.