Well, I havent been down to the park in a while, but I can tell you that the Broad street pedestrian bridge is still alive. I've seen some structural drawings and renderings that are fairly recent, including a nifty night-time rendering which I can't seem to find on the internet
I'm pretty sure this one was publicly released
Correct me if I'm wrong, but I think they began planting those new trees last spring.
But I have no idea about the link between the Science Centre and Centre of the Arts. Are you sure it's cancelled? These things take time. It wasn't too long ago that the conceptual drawings were released. I'm guessing it's still just in the planning phase.