Aerosoft has just released the FSX version of the An-2 as a follow-up to their initial P3Dv4-only version from a few weeks ago.
http://forum.aerosoft.com/index.php?/topic/129659-now-also-available-for-fsxsp2-and-fsxsteam/
http://forum.aerosoft.com/index.php?/topic/129659-now-also-available-for-fsxsp2-and-fsxsteam/