The line is really long so it should move quickly even if it's a long wait...
As for all these questions of "when will it be open" etc... I know the concept of soft opening is somewhat new to aussie parks but what it means is there is a chance at any time the ride will open to guests, and at any time it may close, and without warning. You may get stuck on the ride, or be about to board, and then be sent away.
A soft opening is used to get the bugs out of the ride system (of course nothing safety related) and the operations staff themselves so that when the ride officially opens and the park gets slammed the ride and staff are 100%.
If you want to head to the park on the chance it will open, do so, but you might wait all day and never get on, and you can't complain about that, it's a bit like beta software.
The park can't update on FB when it will open and close because they might not even know until just as it happens, so many variables.
As for the ride, I've had a chance to ride and I think its friken amazing. Not "better than superman" as that is what everyone asks, rather it's a completely different style of ride and whilst doesn't have the speed has heaps to offer in it's own right in my opinion. I don't think it will have as big of a mark on the world scale as Superman, just simply because Superman is the best themed excelerator out there with one of the punchiest launches and the coaster world loves accelerators.
Green Lantern is certainly a kick ass coaster though, has had some awesome extra touches added to it by Movieworld (IMO the 4 accross cars and lapbars make the ride) and when I enter the station I even get the 'feel' of a big brother coaster from overseas. In terms of the winner for the Gold Coast this year it's definately going to be GL over the competitions offering.