I've been meaning to post something on this for a while, and have been swamped with work, but popped in here to see a diary on this issue. This is exactly the same mechanism that was used in 2004 on MyDD throughout the election.
As it says, when you click on either of the map counters of EV's:
"This Electoral Vote Map is updated constantly to forecast the 2008 Presidential election based on the latest available state polling."
The very latest poll in each state, without weighting or averaging.
There isn't a bias as to the pollster, if you see the poll listed as credible on Pollster.com, or RealClearPolitics.com, it'll be included. But, if the latest poll is tied, then the result remains the same as the previous latest poll.
This is a forecast made by the very latest poll. If you see a mistake, perhaps a poll was missed that is the latest, then point it out, and one of the admins will make the change.
The forecast isn't a prediction of the election, but a simple up-to-the-minute poll temperature of the state polling.
(update) And yes, you can edit the map yourself, as one user explains:
1) When you first log onto mydd, it populates the two maps with the most recent single poll for each state.
2) If you then click on the map and change it (for example, you don't believe that Hillary would lose WA to McCain), the numbers update to your settings - now it becomes like an EV calculator
3) The next time you log on, or refresh the page even, the counters go back to their poll-generated state.