Jack Corbett posted the official announcement to his blog - I'm posting here as well to make sure we reach as wide of an audience as possible.

I know how anxious speakers get when you're waiting to find out if your abstract has been selected for a major event so it's disappointing that we had to make the change. However, we also want to make sure not to rush into voting and have it end up being a debacle. After weighing the options the best thing to do seemed to be to wait a week - not entirely a bad thing as it gives people more time to opt in for voting that we hadn't factored into the schedule before the holidays began.

We hope everyone understands the reason for the change and appreciate your patience.