Sony has <A HREF="http://www.pcworld.com/news/article/0,aid,113687,00.asp">dropped several features from its upcoming PSX</A>, a combination video and gaming device. The company has not been able to complete development in time for the year-end sales period, Sony said Monday. PC World says there are two reasons for the changes. The first is to make the device easier to use. The second reason is that development of some functions missed deadline and had to be left out.