I saw a newspaper article here where public places are going with "Seasons Greetings" and keeping it generic, Dodge. The christian spokesman said it was all a plot to take Christ out of this holiday, and it was an attack on them, and other people had no right to try and hijack their holiday. And that was just for being generic, not all inclusive.

A google of "non denominational xmas" gives a few sites tjj.

Happy Holidays, Seasons Greetings, Seasons Wishes, Holiday Greetings, Winter Festivity, Peace On Earth, Tis the Season, Celebrate the -Light -Season -Holiday -Child etc.... Let It S*** (wait, four letter word - no s***!!)