Heartily. That's the essential answer. We aetheists attack Christmas with passion and gusto, embracing the spirit of giving, gorging and partying with complete abandon. We have no deep meaning in which to get wrapped up in or feel guilt over. We can indulge in the pagan rituals and other yule-tide inconsistencies without fear of indoctrinated omnipotent retribution or any tut-tutting guilt mongerers clad in pious coats of malcontent. 

Atheists, can bask in the delight of their fellow man, be they Hindu, Jewish or Muslim or whatever... and celebrate a holiday and a day that is about sharing and giving a little something extra back. We do this with glee and to those who say "isn't that sacrilegious," my riposte is this...

Don't be silly - we don't believe in god and therefore have no interest in religion.