Sony's Shuhei Yoshida is great for a lot of reasons. He executive produced Legend of Dragoon (and a heck of a lot more familiar titles in his impressive tenure at Sony). He falls asleep at Sony panels and then jokes about it on Twitter. He also often plainly answers users' questions on Twitter with "yes" and "no."
With this "yes" on Twitter, Yoshida confirmed that the PS4's party chat is inviting Vita users along as well. Cross platform party chat. Chat's a neat feature. Nothing to be cross about here. Unless you're still upset that the PS3 never delivered cross game chat. In which case, wow, way to hold a grudge. Remind me not to get on your bad side.