I think most of the criticism here is of the "I hate it because they didn't include the one specific feature I irrationally hoped they would" variety. There are a few valid complaints about missing features, though, but I think there are good reasons that Apple didn't include them.
First, the camera. Simply put, there is no way Apple can get 3G on a device like this right now if it has a camera or mic. AT&T, Verizon, whoever - that would be their first and foremost demand before going into any agreement. Later, as their networks get better, they will allow it; but not right now. Personally, I think Apple made the wrong tradeoff - I think they should have kept the camera and booted 3G. But that's me, as I wouldn't see myself carrying this around. Students, business travelers, Starbucks junkies - I'm sure they'd feel otherwise.
Multitasking is a matter of Apple finding an implementation they're happy with. When they do, it will be added to both the phones and the pads. My feeling is that they are trying to come up with a UI enhancement that will solve both the multitasking and document problem. It's not an easy task, given the original UI is so app centric. Give them time.
My big question is iTunes streaming. I may have missed it, but I'd think that the ability to stream music and video from another source would be something they'd tout if they had it.
I think the device is a bit small for useful content creation. The iWork stuff looks cool, but I'm having trouble imagining using it. What this tells me is that Apple is probably thinking about larger devices already. Which brings me to the interesting comments from a few of the Apple guys about this being "the future" - I wouldn't at all be surprised if they see these devices eventually morphing, both in size and UI, to replace the laptop.
I also thought there were some gaps in the presentation. I suspect there are some unfinished negotiations that would have led to additional content. Though I don't think TV was ever one of those - those guys are idiots, and Apple and others will have to drag them kicking and screaming into the 21st century. I expected two things - a magazine demo, and an interactive book demo. Specifically, what I expected wasn't an eReader, but rather a development of iTunes extras into something that could serve the print industry better than the choice of either generically formatted text or rolling individual apps, which is what we seem to have been given. I'll keep my fingers crossed, though.
All in all, I think it's a good device. Probably not worth the preliminary hype (these things rarely are), but a good, solidly thought through device that I think will sell well.
Except it doesn't have an external brightness control, which is a total deal killer for me.
