Sun Delivery send out a letter that they are very busy with orders and as such delivery times might be extended somewhat during the Holidays. Normally they delivery in 2.5 to 3 weeks, and I think it would likely mean you may have to add another 5 to 7 days on top of that service window.

Also, the cut-off date for Christmas Delivery for them is December 1st. All orders have to be in their hands by 12/01/12 in order to be guaranteed for Christmas.