This nightly would bring Android 4.2.2 to the S2...
Steps:
1. Downloaded cm-10.1-20130216-NIGHTLY-i9100.zip and copied to internal SD. Verified MD5 checksum (e6160d0492a642221e64d7f98f726fdf).
2. Reboot into CWM Recovery.
3. Created backup.
4. Flashed cm-10.1-20130216-NIGHTLY-i9100.zip
5. wipe cache partition.