There is no way known that the iPad - especially as it exists today, but even with promised (or speculated) changes in the near future - is going to cover all the requirements of "90%" of users.
I've brought up most of the things you've talked about before the first iPad was released and frankly there's no arguing with fanboys. Steve could sell them turds wrapped in silver foil and they would come up with some reason to buy them (they're collectible and they're from Steve!!!).
What bothers me about the iPad is that Netbooks can be had for as little as $250 that have a 10" screen, 250+ GB hard drive, 2GB ram, external monitor connection, USB 2.0 (3.0 is starting to show up) ports, web camera, built in 90% sized keyboard and they run the FULL version of Windows (XP or 7) and in many cases with a little hacking the full version of OSX Snow Leopard. I know. I own one and I bought it with the full knowledge of what the iPad was going to be and that is EXACTLY why I bought it.
I can carry a little mouse with me and have full blown working setup on the go that is fairly ergonomic and takes up very little space. Because I'm using the full version of OSX, I can actually sync my iPod Touch (or an iPad for that matter) to it. It has 320GB of storage so it has plenty of space for music and movies to take with me and it has VGA out so I can connect it to most newer TVs and monitors with ease (even in some hotel rooms). No, it's not very fast. In fact, I think the iPad's processor is a bit faster, but that just drives home the point even more that the iPad COULD easily run a full version of OSX.
Now the iPad starts at $600!!! For $600, I can get a full sized notebook in the PC World and I don't mean a total piece of crap either. People like to point out that the iPad isn't an iPod Touch (no, the iPod touch has 720p video an facetime cameras and the iPad has nothing). Yet the iPad offers no more connectivity options than an iPod. There's no SD slots (even just to load music movies or photos while on the go) and so you're dependent upon ANOTHER COMPUTER to load anything. Well, that doesn't fly on-the-go! The whole point is that I don't have to carry my notebook with me (or maybe even own one; maybe I only own an iMac and wanted an iPad instead of a notebook; otherwise what is the freaking point? It's the size of a netbook, but it does little more than an iPod Touch + a Kindle.
The new Macbook Air would be a better choice. At least it can run full versions of iTunes and has actual connections to the outside world, not just a nested device for another computer and starting at $999 (compared to say a 64GB iPad at $700) it's not THAT much more; OTOH short of the connections the two have a lot in common. In other words, the iPad COULD have operated the same as a Macbook Air with a full OSX version with only a few additional connectors needed). Meanwhile, the Windows world sells plenty of capable netbooks and notebooks in the $200-800 range, many of which COULD (or even CAN) run OSX with a GPU driver and a little hacking.
It is Apple that chooses to sell overpriced toys with loads of missing features and consumers that choose to buy it anyway. So you can hardly fault Apple here. Why SHOULD they offer more to the consumer when the consumer appears to be perfectly happy buying a giant iPod that is not really easier to carry around than a Netbook or a Macbook Air (you'll still need a briefcase or bag of some kind because none of them will fit in your pocket and the iPad will need another computer to sync) for $600-800? To quote Forrest Gump, "Stupid is as Stupid does, sir."
Until people demand lower prices from Apple by avoiding their products (and making sure they voice WHY they're avoiding them; otherwise Steve will get the idea that they're just not thin enough or something), they'll keep doing what they're doing since you have no other hardware choices to run OSX without hacking (whereas direct competition to OSX hardware would tell Apple exactly why people don't buy their products...i.e. price versus size/performance and style).
Personally, I think it's only a matter of time before iOS and OSX converge even more so than now. A next generation iPad may indeed get a 'more' full version of OSX and Lion is probably a step in that direction. You may start to see standard connectors appear and the ability for it to run on its own and plug in USB/SD devices and possibly some day be able to run a greater variety of software than just "apps". OTOH, you might just see the opposite with OSX shrinking down to not support full sized apps (the removal of direct support for Flash and Java along with Lion's support an "app" launcher and Apple store center) might point in this direction. In all probability, it will happen somewhere in-between the two unless apps for OSX are wildly unpopular or something.
