To answer OP in order:
Pretty sure the PS4 has live streaming and group video for that as well. You can play a game, perhaps even watch a movie or do nothing, and have a friend or more video chat with you. Skype not needed, but I'm guessing PS4 will have skype but MS will have exclusivity on group calls with skype.
Each PS3 and each Vita has 1GB for game saves currently. I don't see a problem with them adding more storage that can handle different types of files. No need to partner with anyone, but I suppose they could.
PS4 will have the ability for multiple apps to run at once. Not sure what kind of OS/UI they will have, no one really is because they haven't revealed it in detail. I'd bet they made their UI more flexible and able to transform it as the generation goes on, similar to the 360. If the current UI is holding it back, they will made adjustments. Hopefully it is comparable to X1, though Snap features are probably out of the question, pause state on all running apps will be just as fine.
I'm not sure what Gaikai's capabilities will be in regards to cloud, but I have heard they hold some of the best patents. For games, I'm not sure if there is much difference between cloud processing and cloud streaming, either way the processing is done over the cloud. As the infrastructure expands, so will the capabilities, and that goes for both companies. We haven't seen anything yet outside of Gaikai streaming demos before the buy out.
I'll be honest, Kinect 2.0 is indeed very nice. Not sure I care about gestures, but if the voice commands are precise that will be very useful. Sony could implement voice commands if the PS4EYE has a mic on it still, but they would probably have to partner with one of the other big voice recognition companies and I'm not sure if voice was built in mind and therefore it might not deliver well if they try it. Thankfully controllers work just fine. The PS4EYE is an HD stereo camera and will have a lot of functions itself, it also expands what PS Move can do and other forms of recognition. Wonder what we will see happen this generation?
Sony has a lot of entertainment in their hold. Music and movies could be part of the upper tier of service subscriptions. Imagine an all in one package. PS Plus + Gaikai and everything involved with that + Music Unlimited + Video Unlimited back library streaming and new renting discounts + and more. Who needs TV right?
Before the PS3 everyone was nice to me :(
