Personally, the most common complaints I've heard so far aren't regarding the camera, but regarding the edges. People seem to want the screen to go right to the edge with almost no border.
Umm... it's touchscreen. Wouldn't that make holding the thing much harder? If you curled a thumb around the edge, it would start touching things onscreen by mistake wouldn't it?
Seems to be intelligent design if you ask me.
Some criticisms seem to be fair, such as the camera for example. That doesn't affect me, as I didn't need a camera on it. But I can see why it could be a problem for many. But most of the criticisms seem very odd. Doesn't run OSX... Of course it doesn't! That would have been horrible! Uses 4:3 aspect ratio.. Of course it does! It's not a television, it's a multi-purpose device. Doesn't handle Flash... Of course it doesn't! Flash is terrible. It's a resource hog, will drain the battery. Bring on HTML5! It's like a big iPod Touch. That's not strictly true, but even if it was, what's wrong with the iPod Touch!?
I hardly see anyone praising it for the exciting stuff. People wanted the option to use physical keyboard. You got it. People wanted optional 3G, with Wifi-only models available. You got it. People wanted to use 3G without being roped into another contract. You got it!
People seem pissed that this doesn't replace their computers. Was it supposed to? I don't think I would have purchased a tablet device to replace a laptop or desktop computer. I'm purchasing the iPad because it ISN'T a replacement for my computers. I don't want to design websites or do programming on a tablet. I've got computers for that. But this is perfect for me to just enjoy! I've wanted something like this just for browsing the web while listening to the music. I love my iPhone and it has become the hub of my entire life. I plan everything I do with it, entertain myself with it, and use it every hour of every day. But I hate pinching and scrolling all the time on websites and I can't wait to see what the devs do with this big screen and faster processor. Bring on the apps!