Looking at the calendar I'd speculate that Christmas Eve bumps aren't going to be very likely this year -- if you're after a bump other than the noise caused by Santa's sleigh landing on your roof you'll have better odds flying on the afternoon/evening of Dec. 21 or the morning of Dec. 22.

Why? Because this year Christmas falls on a Tuesday, meaning Christmas Eve is Monday and meaning a lot of people will be taking that day off and meaning they'll be starting their holidays by flying the previous Friday evening the 21st and Saturday morning the 22nd.

Of course, there are plenty of variables that can mean that any airline needs volunteers on any flight...I just wouldn't get my hopes up for a flight on Christmas Eve.