According to this new rumor, Samsung is moving quickly to get Jelly Bean out for their current flagship the Galaxy S III. Supposedly, an industry insider indicated that Samsung will be ready soon to update the SGS3 to Android 4.1 Jelly Bean, and that it may come as soon as August or September. The insider's statement was, “Samsung is almost ready to update.” Additionally, this same insider also shared that the Jelly Bean update for the previous generation Galaxy S II phone is already in testing as well, although that one could take a bit longer.
Obviously, we will be watching this one closely and inform you when we get more info.
Source: S3Forums via AndroidAuthority