Let me preface this by saying that I am by no means a casual tablet user; I'm a tech geek. I got the original Nexus 7 on the release date and I have been lucky to get the new Nexus 7 before its official release. I will be reviewing this tablet as it suits me, and my needs from a tablet are most likely going to be different from those of the typical user. However, I'll do my best to shed some light on this tablet even if I've only had it for a couple of days. I'm going to be dividing my review into several sections.
Design: The new Nexus 7 definitely is lighter than its predecessor; that's apparent right away. While it isn't quite as thin as the iPad Mini, I am not one to get into the hype on thinness. It is thin enough, and that is all that I care about. One of the things highlighted by Google was the thinner bezels on the side. This may just be me, but I don't really like the new bezel. I like resting my thumbs on the side of the device and it seems like I won't be able to do that anymore. Also, the top and bottom bezels look a lot longer. (I don't know whether they actually are or that is just how they look in relation to the thinner side bezels.) I use my tablet almost exclusively in portrait mode, so this new bezel layout doesn't suit me too well. However, if you like using your tablet in landscape, I can definitely see how the new bezel layout would be an improvement. Maybe I'll get used to the new bezel after a couple weeks of use.
Screen: I was more than happy with the 720p screen of the original Nexus 7. It looks even better with the new 1080p screen. However, the thing which was even more apparent to me than the higher resolution was the increased color saturation. Everything on my original Nexus 7 seemed washed out and dull, but that is not the case with the new Nexus. And there is no flickering or any of the other issues the original nexus's had. Also, a thing that is worth mentioning: with my original nexus, I noticed that sometimes when I tried to flip between home screens with a very light stroke it would not register. It would flick back to the screen I had started at. This seems to have been fixed with the new Nexus 7.
Speed: The 2GB of ram on this device are absolutely crucial. That was (in my opinion) the main thing holding the original nexus 7 back. While the new processor isn't the snapdragon 600 we were all hoping for, it is far better than the Tegra 3 processor in the original nexus 7. Note for people considering upgrading: the architecture of the Tegra 3 doesn't allow for Open GL 3.0, so original Nexus 7 users will not be getting it. Overall, the speed of the tablet doesn't appear to be much faster; the original nexus 7 is by no means slow. But I feel that with time the speed difference will become much more apparent.
OS: Android 4.3 is nothing new: far from the long awaited Key Lime Pie. It is a great operating system that functions well, but if you are looking for a new interface, look elsewhere.
Speakers: They are a definite improvement over the original nexus 7. I wish they would have been front facing, but you can't get everything you want.
Cameras: The cameras are nothing special. Your phone most likely has a better rear and front facing camera. But for video chatting, they work well enough. I personally have no need for the additional rear camera (and I refuse to look like a fool taking pictures and videos with my tablet), but I do know others will appreciate the rear camera.
Overall, this device improves on the original Nexus 7 in nearly every way. I haven't gotten too much time to test everything on the device (cut me some slack; I've only had it for two days) but from what I have seen, it looks to be a good tablet for a great price. At the moment, it is the best 7" tablet on the market - no doubt. If you don't have a 7" tablet and are interested, you should definitely buy this. If you are considering upgrading from the original Nexus 7, then it matters what your individual preferences are. If you are frustrated with the old Nexus 7's dull screen, lack of a rear camera, or like living on the cutting edge of technology, then you should definitely jump on the new Nexus 7. For $229 and $269, the Nexus 7 is a no-brainer.
One gripe I have with the new Nexus 7 is the lack of a new name. It makes writing a review much harder because I always have to refer to it as the "old" Nexus 7 or the "new" Nexus 7. But that has nothing to do with the device. :)