Games that arent camera related can very easily or more easily be camera related improving various aspects of them that is if the camera is included in every box .
Frankly its a promise a bet for the consumer but if it goes right devs will see value (especially indies) and unique titles will start appearing,titles that would had never existed with just the decision of not having the camera in every box so in the end gamers win core gamers at that.
Eh I don't subscribe to that train of thought anymore. Every big multiplat game still has the PS4 and Wii U to consider so Kinect features will always be non integral to gameplay, even with it being included. Also it will be pretty easy for devs to port Kinect features like voice commands and head tracking to the PS4 versions, even though the PS4 camera isn't included.
Look at motion control in the DS4. That was forced on every system, yet hardly any games use it. Kinect v1 wasn't forced on every system, yet that received tons of support and most big titles had "better with kinect" features.
I think it really just depends on the quality of the peripheral. A great one doesn't need to be packed in to get great support. A bad one will get bad support regardless of being forced or not.
A 300 dollars device will never be adopted on top of another 300 dollar machine no matter the quality, the kinect v1 had great support but most of the games sucked because the bet in it by 3rd parties wasnt big enough and MS failed to showcase the kinect v1 in that regard too the solution is to implement it in every box.Bigger crowd=Bigger bet=More complex use of the platform.
Porting will be an option but dont expect the same quality or depth for example i dont see ps4 doing these.
-Identifying the player in split screen mode so that each has the screen of their controller
-Quick navigation and finding via voice (could eventually use)
-Reading heartbeat ideal for fitness or horror games
-Activating pre paid codes by just looking at it (no longer need to input a long bar of activation codes)
-See in the dark
-6 people tracking
-3rd parties have actually shown interest in the platform -BF4 ,Kojima, that game company ,COD ,Harmonix . where is the ps4 camera support just playroom?