It'll survive until the famed NX.

It wont be sony´s last portable. They wont give Nintendo 100% handheld market.

Personally I think Sony should make a Vita skeleton that you can slot any 4.5"-6" phone that meets minimum processing specs into as the main screen (say the Xperia M2 or better). And they should develop downloadable games that will run on the minimum specs, as well as develop more demanding games that will run through PSNow.

Every few years they should up the minimum specs for future game development. Older spec'd phones will still be able to play PSNow games and will still be able to play the back catalogue. But new games will only run on phones that meet the new specs.

Yeah but they dont spend any money anymore on producing games yet getting 15% of all games the other devolopers still do. Their only problem is the amount of oversupplied hardware. 

PlayStation Portable was Sony's first and last handheld. PlayStation Vita at launch was a full on Phone. I have used my 3G Vita as a phone for months now, and wish I would have never wasted money on Android and iOS phones over the last 3 years. 

With that said, how long will the Vita last?

I would say that all depends on PlayStation Network. If Sony gets PlayStation Vue, PlayStation Video, PlayStation Music, and PlayStation Now working on the devices seamlessly and effortlessly, then the Vita thanks in a large part due to the PS TV will live for quite a while. If Vue takes off in the next year or two, then we may even see a huge turn around for the platform. 

I believe the PS Vita OS will live on and evolve for decades, as I see it returning for whatever Sony does next in the mobile gaming market. This is the foundation of their mobile furtue for an all Sony consumer, from the hardware, to the software, to the networked services, and beyond. 

In fact due to things like PS Now and Remote Play. A future Sony handheld does not need to be any more powerful than the Vita in all reality. A Vita 3000 with a couple of GB of RAM to open up multitasking, a better battry life, and 4G would turn Vita into a very good little mobile device that could easily sway people away from the current smartphone market. Not only would it have all of the things the majority of people use a smartphone for, but it would also have access to everything from current AAA titles to indies. All from the largest gaming network in the world.

No I have not held a vita TV. Here's the problem. If it's the size of a modern day smart phone it will be too small to play real games on. If its too big, say, the size of a vita, it won't work as a cell phone. Get the point? Why do you think no ones attempted this? Do you honestly believe random users in this forum were the first to think of combining a handheld gaming device with cellular functions? It. Won't. Work. 

Look at how mobile games are designed. On the fly, pop in for five minutes on break and drop back out. Most games even have energy that needs to recharge so you can't keep playing (because they're free to play). If you're going to spend serious down time playing a handheld, it needs to be robust in its primary target - gaming. It literally makes no sense to try to Frankenstein a cell phone with a dedicated gaming handheld. If it did, I promise you we would see something by now. 

And I pray that Sony isn't arrogant enough to try to compete with Android or iOS. Thats the last thing they should focus on right now.

It should be around for quite awhile. There really is no need to drop something that is seeing a lot of support and generating good revenue. We know for a fact that indie developers in the west and Japanese titles are doing quite well on the platform.

Honestly, it wouldn't surprise me if Sony pulls a Nintendo and releases a "New" Vita in Japan. Updating the insides and keeping the outside roughly the same would be a good way to cut costs.

Sony is likely looking at new possibilities as we speak. I think they will have some kind of product in the portable gaming space, though it might be in a different form than a traditional dedicated device. I have a feeling anything they release will play mobile games natively. That's way, way too big of a market to ignore. I think their next portable gaming hybrid will surprise people.

Does that mean then that the PSP is more powerful than the Dreamcast and its not even an arguament, purely because that link says it is?

Sorry, the PSP and 3DS are a hell of a lot closer than people think.   Ridge Racer 2 on PSP has not been topped yet on 3DS for graphics, neither have games like Tekken 6, Ghost Of Sparta, Nayuta No Kiseki, Kingdom Hearts, Crisis Core etc.  None of those would look out of place on a 3DS whatsoever.  

as long as the others, altough it makes the whole time not so good selling, but its great to see the vita in the shop