A listing for the LEGO Seasonal Santa Set (850939) has shown up on LEGO Shop websites in Europe. This set comes with Santa and a child minifigure along with a small train and presents. Included also is a wig so your can change the gender of the child minifigure.
It’s similar to the just released LEGO Seasonal Halloween Set (859036). As with similar sets, this one should be available in the US soon and retail for $7.99.