Share your experience!
I had the same problem. I just downloaded the 4,2,2 upate manually and used flashtool to flash the android. This does NOT oid your warranty. Here is the guide and the files i used :
http://forum.xda-developers.com/showpost.php?p=46931803&postcount=54 ( to combine all the files , select all the files and after that just click on extract ( 7-zip ) and chooose a location , if you did this correctly you should have a file thats about 730MB in size 
Guide : http://www.xperiablog.net/2013/05/30/install-jelly-bean-to-your-xperia-s-using-flashtool-tutorial/ ( it's for the S but it works the same as for the L)
Goodluck! ( remember to backup everything on your phone of course)