They are trying to put all the numbers together. The media is doing much the same thing.

there was little to no talk of exit polls in 2008 until the polls closed.

In 2004, the exit polls leaked in mid- to late-afternoon and those of us on DU were optimistic at Kerry's chances. After the exit polls were (supposedly) wrong.... in '08 no media outlet talked about exit polls until later in the night.

Am I remembering correctly.

It's generally agreed not to release data until the last poll in the US closes.

when done by the campaigns themselves, immediately available to them.

As for the networks, they will announce what they know just as soon as the polls in a given state close. They do not wait until all the polls have closed, not even until all the West Coast polls have closed. What they will do, I am almost certain, is hold off calling states until those West Coast polls have closed, if they would then be declaring the winner in the election at that point. It happened in 1980, and the networks were very roundly criticized.

Alaskans and Hawaiians are always resigned to knowing the national race is almost always called before their polls close, but the good people of both of those states must surely remain motivated to vote and take care of the local races.