Today recognized developer arco68 from xda-developers forums has announced that there is now a stable build for the 3G variant (GT-I9190) available at the get.cm website: http://get.cm/?device=serrano3gxx
For now there is no information whether this build has bugs or any other problems, so you would have to flash it and explore for yourself.
- Make sure your phone is rooted and has CWM Recovery - Rooting GT-I9190
- Download the cm-10.1.3-serrano3gxx.zip to your sdcard from the get.cm link above
- Power off your phone, then hold Volume up + Home + Power buttons simultaneously, and you should be in CWM Recovery
- Wipe data and cache
Choose "install zip"
Choose "choose zip from external sdcard"
Select the cm-10.1.3-serrano3gxx.zip file and choose Yes when asked to confirm
- Once it says installation is complete, reboot.
- Flash Gapps (optional) - Download Gapps