Here's my mini review compared to the iPad 2 24 hours after. I think you'll find your answer, Anubis.
1) Screen: surprisingly, if I am in the homescreen or if I am not reading texts, the biggest difference is the color and contrast. Other than that, I can't discern whichever one has the Retina Display. My vision is a perfect 20/20 and I don't wear glasses, by the way. If held about 6" away from my face, then I can somewhat discern pixels on the iPad 2. On the new iPad, it's super super super super (repeat that another 1000 times) hard to discern individual pixels. At 3" away, I still can't see pixels on the thing. But the only thing ultra sharp about the new screen are texts. Very small texts. Big texts look about the same as those on the iPad 2. That said, low res photos and especially websites (all of them) look borderline horrible on the new iPad where there is no text. Think trying to play a PS1 game upscaled to a 70" HDTV and imagine it being over two times worse and you're close. Do the boosted gamut and contrast bring this closer to matching AMOLED? Well, I think so. Black level is not quite there yet, but saturation is certainly on the same level as my Samsung Captivate. However, gradations don't have as much banding, and it looks overall more smooth and pleasing.
2) Sound: my assessment yesterday was that the new iPad sounded the same as the iPad 2. That is... until I found out my 3.5mm cable was faulty. So earlier today, I plugged new cable in, connected to amp, turned amp on, connected my trusty Beyerdynamic DT990, and... sure enough, there was a huge difference. The new iPad has more extending high frequency and puchier bass than the iPad 2 out of the headphone port. More over, through LOD, soundstage improves a lot, and it sounds a lot cleaner! I'm truly impressed! It might be the best sounding mobile device I have heard in a long while. I wouldn't mind using this as my main listening device from now on (MBP used to be the one).
3) Performance: this is a mixed bag. If I go into a game and get out, the new iPad behaves like an iPad 1, which is to say... nothing stays loaded in for long. If I don't game, then sure enough, I can keep 5-7 tabs in Safari running while having push email, Yahoo messenger, etc... running in the background without breaking a sweat. I guess gaming does take a huge toll on that RAM. That said, though, the new iPad is generally smoother than the iPad 2 at just about... anything. I wouldn't call it faster, but it does feel a lot smoother than the iPad 2 on average. Heavy web surfers like me would also appreciate that the address bar won't cause lag anymore when it tries to remember all of the addresses that have gone in. Then again, it's only been a day, so I think it's too early for a verdict, but I'm liking it so far.
4) Battery: I used the device up until 8AM this morning, when the battery reported 7% left, and it has been plugged in constantly since. It's 5:40PM now, and the battery reports... 89%. On the plus side, I unwrapped the device at 3:00PM yesterday, when it reported 80%, and used it all the way until 10:30PM, and then from 6:10AM to 8:00AM.
5) Heat: not enough to fry eggs with, or in fact, not even enough to warm my pants, but definitely enough to warm my hands, which is nice. It has been cold out lately.
My conclusion: this sucker needs movies higher res than 1080p. In fact, I think it needs a whole new interface altogether. Current iOS doesn't really show off just how good the screen actually is. Everything seems overly smooth. But I'm definitely keeping it, and I'm dumping my Kindle. It's sooooo awesome at viewing high-res PDFs. There is practically no reason for me to zoom in to any of my books anymore. None. Plus it runs smooth (when games are not involved), and that's all I ask.