The glass is not standard glass. It's aluminosilicate which is 20 times stiffer and 30 times harder than plastic. It's the same glass used in high speed trains and helicopters. The rim is a unibody stainless steel design. It will be by far the most durable iPhone (or smartphone) ever.
The 5MP camera they designed will be better than other 8mp cameras on the market because the sensor size is larger. The larger the sensor size is, the more photons (light) each megapixel takes in. This creates more lattitude and less noise, resulting in cleaner pictures. The trade-off is the resolution is not as high as 8mp cameras... but 8mps of resolution is overkill for a cell camera, and even for a lot of standard point and shoot cameras. Unless you are outputting pictures to very large print formats. The more important part is the quality of the image.
While it's true the video chat has been done before, it's likely iPhone4 will do a lot towards making it a ubiquitous communication technology. No screen names to setup, works with your standard phone calls, at high quality, the convenience of always being with you.
While it is currently only on WiFi, meaning it will be for home, office, or coffee shops (or airports/hotels) only... WiFi hotspots are a dime a dozen and everywhere. The phone auto detects if you are in WiFi so you dont have to fiddle with settings.
When networks support this over 3G/4G things will REALLY take off. The nice thing is that this is an open standard. Meaning other phones can utilize it and communicate with the iPhone when the support it. It's also open on the iPhone, which means we can expect to see it integrated into apps like Skype, allowing you to do a video chat from your iPhone to a skype user on a Mac or PC.
Finally, ATTs generous 6-month advance for an iPhone upgrade can only be indicative of one thing: an impending announcement of their exclusivity ending and the phone coming to other carriers. While else would they be so eager to get everyone into another contract ASAP? They also upped their early termination fees. The rumors have been flying... verizon iPhone... coming soon!
The new hardware combined with the new software of iOS4 leave me very impressed. Looks like the pressure from Google and others has really caused Apple to step it out and bring out their A-Game. It's been a while since I've seen the keynote announcements and left fully satisfied and impressed. The only disappointed was no 64gb model, but that is forgivable considering everything else they have packed in.
Also: gyroscope. I see this as being indictivate of the iPhone/iPod touch being used as a Wii type motion controller when the new AppleTV adds app/game support.
ALSO I want to agree with tokenz. Thank you TOMs for consolidating this into one article and not spamming the news with 10 different stories!