This info is all over the web.
"SGS III will be more incremental update than bold new flagship, insiders claim, boosting speed and adding a new eye-tracking control system but otherwise being more of a Galaxy S II refresh. “It’ll be like the iPhone 4S was to the 4″ a UK telecoms source told CNET, referring to the more moderate changes Apple made to its smartphone late last year, despite persistent rumors of outlandish improvements. Meanwhile, Samsung might not even call it the Galaxy S III, according to the tipster.".
It may even turns out that Samsung will name its next flagship phone as the Galaxy S3 - using numerals instead of numbers.
At the moment there is nothing certain. We have to wait for the London event. Be patient !