We now have more information about Demons Souls 2 and Project Beast for the PS4 and it does seem that the games are one and the same.
It looks like some things are shaping up in From Software as there is word going around that they were working on Project Beast with Sony Japan Studio. Dark Souls will be a game for the PlayStation only and of course Project Beast had help from Sony, so this means it could be out on the PS4 only.
There have been leaked images from Project Beast and fans believe that we might hear something about the game at the E3. When you see the images that have leaked you can see that it is related to the Demons Souls game. This could mean that it and Project Beast are the same game. However it could be that the former may have been used as just the code name.
At the moment this is nothing more than a rumour, so do take it with some salt.