They CAN use it right now but non imps suffer a penalty. It is being tweaked such that Gobbos no longer get the penalty. Nice.
Ummm...you people are clearly not reading his reply. "...will conform to the OUT OF GAME description." Meaning non-imp gets -4dam -1 spd...sorry gobo lovers...
In this context, 'out of game' means the description on the rune card, as per Sok's reply. Gobbo lovers rejoice!