WMS has estimated December sales of 1.3 million Wii hardware units and 600,000 PS3 hardware units (200,000 PS3 hardware units were sold in November). The analyst says Xbox 360 sold 1.2 million units in December. Image December U.S. retail software sales should be up by 15% year on year according to analyst Wedbush Morgan Securities. In his monthly pre-NPD note, Michael Pachter forecast sales of $1.8 billion, up 15% compared to last year's $1.6 billion figure. The estimate reflects $927.5 million in sales contribution from new platforms (PS3, Wii, 360, PSP and DS), representing year-over-year growth of $600 million, or 183%. WMS expects current generation software sales of $947.5 million, reflecting a year-over-year decrease of $361 million (-28%). Sales growth over the last six months has averaged 16%, and WMS is reckoning on 25% monthly software sales growth in January and February. The forecasts reflect a slight decline for PS2 software sales (-3%), but a much more considerable decline for GameCube software (-67%) and for Xbox software (-63%). WMS says the tie ratio for Wii and PS3 leveled out at 2.5 in December, following a poor start for PS3 in November. The U.S. hardware installed base currently stands at 18 million next generation consoles (including handhelds) as of the end of November 2006 (up from 8 million at year end 2005).