Well, the browser has tabs (at least, the iPhone Mobile Safari does, so it's no stretch to think this does as well). The lack of a camera is, I agree, silly.
Rather than rebut the rest of his "points" directly, I'll focus on "multitasking". Frankly, the iPhone and iPad do multitask, in the ways that are important to (most) people. Multitasking in an end user product really means "I can do more than one thing at once", not "The computer runs many processes". The iPhone OS currently accomplishes exactly this, via saved state.
In any well behaved iPhone app, if you quit, the state of the UI and your data is persisted, so that when you return, it's like you never left. The UI for this multitasking is a bit clunky - hit "Home" then pick the app - but for most people, this works fine. There are only two situations when this doesn't - when the app does something interesting in the background, and when the "stack" of application interactions collapses - if I click a mailto: link to open Mail, quitting that doesn't return me to Safari - I have to go there again manually.
The two cases of "Does something interesting in the background" that really people want are audio streaming and notification of some event, and they're real problems. However, Apple's persistently said they're trying to protect the user experience (stability, battery life etc) by denying background apps. I've no reason to believe this isn't the case (I'm mean really, what are they gaining except geek ire by restricting this?). The audio case is annoying and needs a solution - the notification case is slightly better since push was rolled out.
Outside of these cases, the iPhone multitasks well enough for 99% of the world. His reading case, catching up on the news etc all are handled - you just have a slightly painful app switch process (i.e. you press two buttons rather than just one). The only case that isn't is background movies/music from 3rd party apps - and really, the only sensible case out of that is music (Do you really watch a movie and browse at the same time on a 10" screen?). Regardless, I suspect the point will be moot soon enough - OS 4.0 seems very likely to bring some notion of background processes.
The geek anti-iPad ire really confuses me. What did we expect, other than what we got? It was never going to run OS X - the user experience would have been awful without major changes that broke all 3rd party OS X apps (and then, what's the point?). The hardware, modulo camera, seems entirely reasonable at a price that's damn good - who realistically expected anything more from an affordable tablet machine at this point in technology? The "walled garden" is a real issue, but I think we have, as a group, gained far more than we've lost with the App store. All these people saying "I could never have been a tinkerer with an iPad" - poppycock. Download the SDK for free, develop all you want. Pay a nominal fee to deploy to 100 other devices without ever giving Apple a look at your app. Or hell, just jailbreak it if the limits of the SDK are so onerous.
Alternatively, just don't buy it. Having chosen this please, stop filling up HN/Reddit/The Internet with "The iPad doesn't raise the dead, make me a billionaire and cure cancer, so all my dreams are shattered and Apple is awful".