sony mobile communication has rolling out new firmware updates for live with walkman (wt19i) by august 16th 2012. the new firmware build number:4.1.B.0.587 ICS 4.0.4. if you need *.ftf file for offline flashing here is the download links:
extract *.rar file before flashing
WT19a 4.1.B.0.587 Americas
WT19i 4.1.B.0.587 1254-1887 Turkey
Games are now working damn fast and smooth... same as GB
Rom is much more smoother and faster
Dialer is pretty faster
Camera is faster
Better video recording
New base-band 77
New base-band is faster in response
Some what less battery drain than previous .431
Better RAM usage
Some more minor changes.....
LED is working for only call!**
HOW TO ROOT THIS FIRMWARE: THIS WAY INTENDED FOR UNLOCKED BOOTLOADER ONLY!!
- the unlocked bootloader is easy to get rooted, just install the custom kernel that have CWM recovery (e.g rage kernel v3.2 or kamarush lite v3 kernel via flashtool. how to install custom kernel?? see this.
- download the Superuser-3.0.7-efghi-signed.zip
- place the downloaded zip to sDcard, restart phone, enter recovery mode with pressing vol. down button, and then install zip via cwm.
Source: xdadevelopers, thx to sravan242
DOwnload all xperia 2011 official firmware