Largely, I'd consider all brackets dead during the day since they split the East / West servers. Yes some games fire, but they are not of very good quality.
Games typically pick up at around 3:00pm EST from my experience. But honestly, those games are pretty low quality as well. At night (Usually 7pm and later) games are pretty good (lots of twinks, back and forth action) with reasonable queue times.
I hope they revert the split, but if they weren't going to do it this week (following all of the complaints on the forums), then my assumption is they will never do it. It is a little boring to play against the same people over and over, and I have a feeling now that the AB bump is dying down we'll see a lot less people in the bracket, meaning longer queues and less variety.
To answer your question, I think the bracket is not dead, but is dying. And beyond the two or three guilds that can organize premades, I wouldn't be surprised if the bracket comes close to dying out other than weekends.