I don't think such a partnership is possible, at least not in the way you imagine it. Why? Because of money. I'm sure Sony would want some of Nintendo's handheld profites, and I don't think Nintendo is willing to share those. If they made the HW together, that would mean Sony gets some of all the license fees from that handheld, and it's quite obvious that the 3DS is doing fine without Sony. I'm not sure how a phone would work though.

As for home consoles, I don't think Nintendo is willing to give up their right to make any HW they want, which means that they would have to co-develop the next consol with Sony. Which of course means that Nintendo would get some of the license fees from all 3rd parties publishing on that console. And why would Sony share? They don't need Nintendo to make money on that front.

What you've described is a pipe dream.

Sony makes the home console hardware and Nintendo makes the handhelds (with suggestions from Sony first parties that will actually be working on it). The home console is designed to be $400 and the handheld $200. The studios that are good at handhelds for both companies are assigned to do handheld games, obviously quality assurance people would have to approve any IP swapping or new studios working with old IP. Same with home consoles. Nintendo doesn't have to use the extra power if they don't want. Nintendo gives Sony some pointers on how to make a franchise not get worn down (1 or 2 entries a gen for a start). They use the foundation of PSN for their online and put Sony characters in Smash. Win, win, win, win, and freaking win it's gaming NIRVANA!

The trick would be to set up shared royalities wherein both sides make more money than they are making today (hard to argue that). 

Sony has the stronger console brand, so they take the lion share of console licensing fees. 

Nintendo has the stronger handheld brand, so they take the lion share of portable licensing fees. 

Still, potentially together you might be talking about 150 million PS4/Wiistations + 150 million Nintendo/Sony handhelds. 

That's a biiiiiiiiiig pie. Even if Sony was getting a 70/30 split of console royalties and Nintendo was getting a 70/30 split on the handheld side, the 30 percent would likely mean a lot more money than what Nintendo is currently making from consoles, and more money than Sony is currently making from handhelds. 

Sony would be getting a host of benefits, a lot more money from handhelds, a potential sales driver for their cell phone division, and a wave of exclusives on their consoles too that would tip the balance of the console irrevocibly in their favor. It's definitely to Sony's advantage to get to Nintendo before perhaps Apple or Microsoft start throwing bags of money at them. 

It could work, but that would be too much awesome.

I never want that to happen. Playstation brand is something unique born out of passion. I want Playstation to be like this something special instead of messing with Nintendo

Wii Station is weak... 'Nintendo Playstation' sounds impressive... Two huge names rolled into one. Imaging how amazing it would be to have all upcoming Wii U & PS4 titles rolled into one machine. Xbox would be doomed!

I think more than that even it could the answer to both companies' problem with the rise of cell phone/smartphone gaming. 

I just read that Japan spends more on smartphone apps than any other country and the no.1 apps being downloaded are games. 

No wonder companies like Square-Enix and Capcom are running to embrace smartphone gaming. 

If Sony and Nintendo don't offer an answer to this, they could be looking at an industry of kids who've grown up on $1 games and may be only buy the occassional $60 game ... which in the long term dooms both of them. 

Better to make your stand now, together and create something new. For Nintendo they're not a cell phone company and likely would eventually have to parter with someone anyway, why not with Sony that has a cell phone division and has Japanese staff that they can more comfortably collaborate with (Yoshida for example is very complimentary of Nintendo). 

To be honest I don't know how many PS fans want to play Mario or Zelda but something tells me that they r not many else they would buy a Wii not a PS in my case the only thing I care about Nintendo IP's is the Fire Emblem series & the Xeno series from Monolith Soft that's it so for me it would be better for them to stick with handhelds & start making games for other consoles that way they can reach every1/anywhere & they can have max sales much more than what they r going to have now with Wii U...

Are you crazy? Wii U sells are almost the samel like Xbox one and PS4 sells. The numbers are so near. Not exaclty the same selling numbers, wii u is a little bit behind the brand new consolse and this is normal, but the time will come which wii u get more sellings like the BRAND NEW consoles. And Vita got worse selling, but I think vita can also rescued.

Or they could just continue going their own way.