Implications:
1. Since most developers bought during the G version release (and since internationally this is sort of the primary version), more developement was going on for it. Hence more custom ROMs etc.
2. The G version has a different chip, which has been seen to have lower performance, especially in the GPU department.
3. Many ppl reported hangs and camera issues/sd card issues initially when g version was launched. Sort of like more problems. Most of our forumers will tell you it's better these days, or can be solved with custom stuff.
Will it affect s3? Who knows. Time will tell. Unless they have shortage of chips, or unless the new chip proves to be unstable (which seems like bollocks, would have gone through alot of testing before being put into production phone), this shouldn't be the case. Then again, no one expected the variant for s2