While I do agree that Skype on the PS4 would be nice (they have it on the Vita, so I don't think it would be such a huge problem to get it onto the PS4 as well), I really don't think it's necessary. I already have Skype on my phone, laptop and Vita and I'm sure many others also have a multitude of devices that run this app.
For the rest, Sony really doesn't need to do much. In my book, the system menu is already better, games install much quicker, Sony finally got cross game chat / party chat working whilst MS found a way to break a working system, etc etc.
I don't need the PS4 to do what the Xbox does. If that was the case, I'd have gotten an Xbox.
Playstation has always been the platform with the most attractive exclusives for me, I don't think that will be any different this generation. That should be the most important factor when deciding which console you buy, cause in the end you just wanna play good games on it.