I honestly wish they would go back to some of their less serious, quirkier games and stop teasing the fans if they have no plans to do anything with them. The Vib-Ribbon tease, for example. Was it really necessary to hype that when it was just the original game releasing on PSN? That could have been confined to a blog announcement. This is an area where I have to respect Microsoft; you can argue their being pushed to a distant 2nd is what's making them do the decisions they're making, but the old IP they've teased with bringing back, they seem to actually be doing something with them. The Phantom Dust reveal comes to mind. Tbf though, MS doesn't have a ton of IP, let alone a ton of classic IP.
If Sony can keep doing what they're doing, but give me a true Parappa/UmJammer sequel, a Tomba sequel (or a remake of the 2nd game), maybe some ZOE/Omega Boost hybrid thing and keep up with games like Tomorrow Children and Rime (and, while not strictly first-party, but collab efforts like SFV), I'd be content. That'd be a PS4 worth buying, personally. They have a new Rachet coming yes, but where's Crash? They've only been teasing about it since 2013. Hopefully something of that comes at E3.
A lot of people will probably say that those games "don't have a market" but that comes off as a contrived excuse to write them off without understanding or even knowing how the market would react if they were done properly and marketed the right way. There's always an audience for something and some things have a bigger audience than people give them credit for. A new installment in a lot of Sony's classic IP could be great successes as long as they do what's needed (if anything needs to be done) to retool them for some of today's tastes while still keeping the core of what made those games enjoyable when they first came out. They wouldn't require massive budgets, just a loving, dedicated small team. Plus some of those could give them reasons to try other advertising avenues, or even merchandise.
In the end I really think these games need to happen because it just makes common sense. Why choose not to diversify your console's library with them, play up on nostalgia and increase the appeal of the system to different audiences? It's good to have stuff like Bloodborn and Order and Killzone etc., but I like more whimsical and less-mainstream fare as well. I don't want Sony to fall into the trap of relying on only a few IP that more or less appeal to the same demographic, plus sequels to some of their older IP or new IP that targets different types of gamers could get a big push through PS Now and if PS Now is reasonably priced those games could draw in people who are entrenched in lighthearted mobile games (hopefully the good mobile games).
Can't wait to see what is next from them, as well. Infamous is my favorite open world series, alongside Saint's Row.
