The Galaxy S III will not be home button free 

Samsung has decided on keeping the hardware home button on its next Galaxy flagship.
In our eyes it will be a fail for the die-hard Android users. But we also understand the way of Samsung. Many Galaxy S II users will buy faster a Galaxy S III if the design looks more the same so with home button.

Another detail is that Samsung will use the same 5-column layout as the Galaxy Note.
On May 22 Samsung will present their new Galaxy S III in London.
We of SamMobile will try to be there to fix some hands-on.