Google has yet to release the source code for Android 4.1, but that's not stopping the CyanogenMod team from predicting a quick turnaround for CM10. According to a Google+ post which went up earlier this afternoon, the changes and new features introduced with Jelly Bean should be incorporated pretty quickly in the CM10 build, but some code changes for CM's LockScreen enhancements, Theme Engine and Trebuchet will need to be made.
No promises are being made, but it sounds like CM10 should be available to all
