There were plenty of great looking free serif faces released towards the end of 2011. Here are a few.
Poly is a nice, almost caligraphic old style available free in regular and italic.
Cambo is an attractive old style serif face, notable for the yin shaped ball terminals
With chunky chamfered serifs, Enriqueta occupies the space between an old style and slab serif, coming in regular and bold.
Crete Round is a nice, slightly quirky slab serif. Some of the letters such as the capital L, Z and number 2 have vertical serifs on the end.
Bree Serif is a bold slab serif similar to Rockwell.
Alfa Slab is more extreme, a heavy black weight slab serif
Exljbris has released a new version of the popular art deco Geotica for the new year
Unna is a relatively low contrast Didone style hair line serif