You cannot play PlayStation 4 games on a PlayStation 3 as the disks and disk readers are different meaning that their readers cannot read the disks properly.
No and neither console plays the others games
In short, no. Sony haven't released any information regarding a PS4 yet, so we can only assume that you cannot. It is highly likely you will be able to play PS3 games on it, that is - if it really comes out.
You should wait for the PS4 to exist and have games before you want an answer to such a what if question. Based on the past when a new console is released the old one can not play the new console games. Why would you buy the new console if the old one could play the games.
No you will not be able to play the games either way. Systems changes on the PS4 allow them more design capability for games and many titles will be released in a downgraded PS3 version. You still will have to have a PS4 to play PS4 games and a PS3 to play PS3 games.
No, there is no plan for PlayStation to stop making PS3 games. The company recently released the PS4 console. PS3 games do not work in the PS4.
No, you cannot use a PS3 disc in a PS4 console. The PS4 is not backward compatible with PS3 physical game discs, meaning that games designed for the PS3 cannot be played on the PS4 system. However, some PS3 games may be available for purchase and download digitally through the PlayStation Store for PS4.
No, the PS4 does not have backward capability and cannot activate (play) PS3 or PS2 games.
You will be able to play it on both the PS3 and PS4 gaming consoles. The beauty of Playstation is that you can access their games and titles via consoles, along with wireless and remote devices.
No, you cannot play online between a PS3 and a PS4 together. Most games that are available on both platforms do not support cross-generation multiplayer functionality. Each console typically has its own separate online ecosystem, so players on PS3 cannot interact with players on PS4.
No it will not
No, the PS4 will only run the games made for the system. But there is a application on PS4 called PlayStation Now which will allow you to play PS3/PS2 games for a price.
You can get a PS3 and the PS4 is not an actual product. If you want a console buy a PS3 because the PS4 can not even be preordered it's release is so far in the future