As you know update is already out. Here is information how to change your customization code so you can update:
1. You need your phone to be rooted. I use superoneclick 1.5.0. for me it works best. Newest versions do not work correctly at my X8. The attached archive X8win is the superonelick 1.5.0. You should enable usb debugging (settings->applications-development) and connect the phone to your pc. If you do not have drivers for the debug mode you can use the ones from the "X8 drivers" archive which i have also attached. After you have the drivers installed ,usb debug enabled and phone connected start superoneclick.exe and press root. You may need to wait 5 or even 10 minutes for it to complete. Wait until you see "Your device is rooted" popup.
2. Install root explorer. I have also attached it. Start root explorer. Open the "system" folder. In the upper right corner of root explorer you will see "Mount R/W" button. Press it. Now go to the build.prop file. Long press on it and select "Open in text editor". You should edit the following items:
ro.product.name=E15i_XXXX-XXXX where XXXX-XXXX is the customization code. For example mine is 1241-3708 but there is still no update for it.
You should replace XXXX-XXXX with the desired customization code for all the lines listed above.
When ready press the menu button (left) while still in the text editor and press save.
3. VERY IMPORTANT - REBOOT YOUR PHONE.
4. After reboot check for update with Update service or PC Companion and it should find it.
If you edit your build.prop on your pc and return it back to the phone you should correct it's permissions so that it can be read by user, group and others and written by group using root explorer.
You can also see the codes which have the update at the sony ericsson product blog:
Customization codes with update so far:
1241-4091 - It is russian firmware but has following languages:
Russian Firmware contains languages:
Deutch (Deutschland, Liechtenstein, Oesterreich, Schweiz)
English (Australia, Canada, India, Ireland, New Zeland, Singapore, South Africa, UK, US)
Espanol (Argentina, Chile, Colombia, Espana, Mexico)
Francais (Belgique, Canada, France, Suisse)
Italiano (Italia, Svizzera)
Nederlands (Belgie, Nederlands)
Portugues (Brasil, Portugal)
Chinese (Hong Kong)
Here is how to check your customization code:
1. Lock the screen of your phone. Press the menu button (left button) so that the screen is lit but still locked.
2. Press the home (central button) and back (right button) in following sequence:
Try several times if you can not do it the first time. when successful secret menu will appear. Go to Service info->Software info and find "customization version"
It should be something like 1241-3708_R3A (this is my code, your will be different but the same format).
CURRENTLY THEE IS NO WORKING ROOT FOR 2.1. Superoneclick and z4root do not work.