Well, Sony Ericsson released an alpha, but the radio is disabled (you can't phone people) and you need an unlocked bootloader to flash it - may void your warranty.
I found this from the Sony Ericsson blog:
What is the timing for the upgrade to Android 4.0?
It is too early to confirm exact timings at this point. The Android 4.0 code was released on 15 November and we are now working hard on merging the new features from Android 4.0 with our current experience, to provide the upgrade as quickly as possible in 2012. We will get back with more details regarding this upgrade, timing and global availability in due course on our blog.
So, release will be more near to april, but you never know, you might get an earlier release
It won't be too long hopefully!