After the Samsung Galaxy S2 now from April 13th 2012 Sony has started the rolling out of Android 4.0 IceCream Sandwich on its 2011 XperiaTM Smartphones.
Initially the software rollout will be made available to Xperia arc S, Xperia neo V and Xperia ray for consumers in Sweden, Denmark, Iceland, Finland and Norway for the next 4-6 weeks. Sony will update the rollout process for other markets soon.
Following on, Xperia arc,
Xperia PLAY, Xperia neo, Xperia mini, Xperia mini pro, Xperia pro, Xperia active and Sony Ericsson Live with Walkman will receive their scoop starting from the end of May/early June 2012.
To upgrade use the PC Companion for windows and Bridge for Mac and follow the instructions.
The latest version of Android 4.0 (ICS) is a very powerful OS, packed with new features and functionality and also requires more resource from the smartphone and this may impact performance in some user scenarios. If the phone’s RAM is greater than 512MB then there shouldn’t be any problem after the upgrade.
Software updates means improvements, so it is the best way to keep the phone working smoothly. These updates bring new features, better performance and speed, bug fixes etc. So make sure your phone runs on the latest software version.
For a detailed step by step information for Xperia Arc S upgrade please refer this guide and Sony Blog.