The thing that strikes me the most is that Nintendo isn't even trying to market is as the next generation in handheld gaming. Whenever I look for 3DS games (I do own one) they're just sitting next to the normal DS games and I can barely make out the difference. Imagine how a casual person must feel. Nintendo's doing so many things wrong when Sony's doing so many things right.
3D vs. OLED - 3D is fun, but not essential. Can hurt eyes, cause dizzyness and eyestrain. Bad for little children. Nintendo also opted for a low resolution screen, making most games look like souped up PSP titles.
Vita's OLED is just beautiful (according to each and every journalist/person that has seen it) and high-res, providing next-generation graphics we won't see for a long time on a handheld device.
Online - Friendcodes vs account-based PSN. You can't even send messages right now on 3DS. How are you going to make friends and add the people you play with online? It's ridiculous. The e-Shop is also pretty bland, not very user friendly and they don't even provide game demos. Not to mention it's very slow.
PS Vita has cross-game voice/text chat, account-based friendslist, trophies, Skype, Facebook, Twitter, etc. You do the math.
Hardware - Sometimes, the 3DS gets compared to the Wii when the PS Vita gets compared to the PS3. Yet, when most people are comparing system to system, the 3DS often gets compared to PSP (which dates all the way back to 2004). The 3DS is a more powerful machine, yet it still fails to impress people that played the best looking PSP games.
PS Vita launch-games look better than Xbox 360/PS3 launch-games, so who knows what the future holds (in my opinion, the future will be bloody fantastic for us Vita fans).
Marketing - Nintendo's trying to sell 3D. But it's really not happening, at all. When the system first launched, they got on the news, but not in a positive way. Various news-channels reported on the supposed headaches, eyestrains and dizzyness the 3D can cause and how it could affect a child's sight. Parents were scared and suddenly weren't interested in Nintendo's latest handheld. Ofcourse, the price didn't help either; people were obviously not expecting a toy company (because that's what Nintendo is to the masses) to release a handheld device for $250. Gamers know the hardware wasn't worth the $250, because it's old and comparable to the PSP. The price has been lowered, but so far it's still not doing the numbers Nintendo wants it to. To add to that, people think it's just another DS, but with a new screen and it looks like Nintendo just hired a couple of monkeys to run their PR this time around. They thought they could sell on name alone, like Apple does.
Sony asked developers and fans; what do you want? You want a handheld with two analog sticks, the best looking portable screen you've ever seen, connectivity with your PS3, a never-before-seen feature for a handheld gaming device (rear touch) and the best online gaming platform ever made for a handheld? Well sure. You want it for the same price as Nintendo's overpriced 3DS? Alright, here you go, you can call it the PS Vita. It's all yours! Now Nintendo lowered their price but they're still scared of Sony; they should be. It's the better handheld in every possible way.
Did Nintendo rush the 3DS? Yes, and it will give them a run for their money this generation. Will the Vita outsell 3DS? Only time will tell. No one can underestimate the power of PokéMon and now Monster Hunter, but I'm sure every person in his/her right mind (so, Nintendo fanboys not included) knows the PS Vita is the better platform this time. It has better controls and more possibilities, an amazing online platform and the graphical prowess to run all of it as smooth as butter.
Sony, I salute you. You are the kings of the videogame industry and you know what we, true gamers and enthusiasts, want in our gaming machines. Now please, tell me a release-date so I can start the countdown.