Samsung Galaxy S II gets some preview CM10 Jelly Bean love in its turn
The thing might not be suitable for your daily driver, as it was just posted by codeworkx over at XDA-Devs, but these earlies catch up very quickly to stable releases, if history is any indication.
As usual, no guarantees that everything will work, and the developers ask respectfully that there is no whining about it until the build is ready to be a stable release ROM. But if you want some Jelly Beans with that GT-I9100, hit the source link below and enjoy.
source: codeworkx (XDA-Devs)
Things that are NOT allowed: