My fall/winter pumpkin porter turned out well, and at our Xmas Eve party last night we also served Jamaican Sorrel (a hibiscus, ginger, and lemon rum punch), mulled wine, hot cider, and egg nog. The local blogs have been featuring other, more innovative winter/holiday libations available at our local bars:

http://www.thehillishome.com/2009/12/winter-libations/

http://dcist.com/2009/12/the_weekly_feed_mulling_it_over_edi.php