Sony announced eleven of its handsets will receive an update to Android 4.0 "Ice Cream Sandwich" by mid-June. The Xperia Arc S, Xperia Neo V, and Xperia Ray will receive the update around mid-April, and the Xperia Arc, Play, Neo, Mini, Mini Pro, Pro, Active, and the Sony Ericsson Live with Walkman will get it by the end of May or early June.
To receive the update, users will have to tether their handsets because Sony wants users to make a "conscious and informed decision to upgrade".
There is a problem with these updates though, is that none of them will be over-the-air (OTA), and will require that owners of these handsets who want to upgrade have to tether their handsets.
This is because Sony wants users to make a "conscious and informed decision to upgrade". All this means is that while Sony are pushing out ICS updates for 11 handsets, those who don't know about ICS will have to wait until Sony push them OTA, if they even bother doing so. I would expect a notification from Sony saying "your phone is compatible for an update, if you would like to do so, visit this site", and that site explains what ICS is, and how you upgrade.
In a post on Sony's Mobile blog, the firm warns that Ice Cream Sandwich is more resource intensive and may slow down your phone.