Sony has released the Android 4.0 Ice Cream Sandwich updates for two of its Xperia devices, the Sony Xperia Neo and the Sony Xperia Arc, and the update should be available now as Android 4.0.4.
It looks like some other Xperia devices should be getting the update at the same time as well, according to the guys over at the Xperia Blog, the Xperia Arc S, Xperia Neo V and the Xperia Ray, which were previously running Android 4.0.3 should be getting the Android 4.0.4 update shortly.
You can find out more information on the Xperia Neo update here and the Xperia Arc update here, it seems that certain devices with particular serial numbers will get the update first.
Source EuroDroid