I personally think its a little silly to wish for things that would so fundamentally change the weight, battery life, cost and purpose of the device that it would no longer be an iPad -- its like wishing that your car had a La-Z-Boy, beer fridge and HDTV in it so it could also be your den. And I know you are thinking right now "that would be AWSUM!"
Some of the requests above also reflect perhaps a lack of understanding of what the iPad is -- it's not
a big iPod, but neither is it a crippled laptop.
If I had to put it in just a few words, I would say it is an simplified internet gadget aimed at people who want a mobile device that does specific tasks extremely well with no learning curve, no maintenance, no configuration needed. It is not intended to replace a "real" laptop, merely to push the full-blown laptop back to the audience that really needs it: professionals. Most consumers have no use for 95% of what a laptop can do.
Geeks like us have internalised and normalised much of the "hassle" of owning a computer so much that we don't even notice that its a hassle. We think clearing web caches and defragging and having to wait 30 seconds for the thing to start up is perfectly normal and everybody should just learn to accept these things.
But "everybody" politely disagrees. Non-nerds do not see a reason why getting on the net or checking email should be any more complicated than operating a toaster (to use the classic example). Many of them just want to surf, check mail, read, listen to music, watch videos and play solitaire. They see no reason this should be so complicated that many of them feel frustrated, afraid and/or stupid when using it. And frankly, they're right.
Apple has been trying all of its "life" to move consumer
computers toward being that straightforward. The iPad is, if anything, the next evolution of the original idea of the iMac: hide the "computer."
Okay, having said all that, I'm not trying to say that the iPad is perfection and does not need suggestions for improvement; I'm just saying that while it's fun to wish, there's a realistic limit to what's practical.
Example: I too would have loved a little webcam on the front, and I think the technology exists to pull that off without significantly adding to the weight or thickness. BUT it would have made the device at least $100 more costly, and been too popular on the already-overloaded 3G network to produce a really satisfactory experience. The mic is sufficient, given the inherent limitations of factors beyond Apple's control.
So as far as suggestions, my main one would have been a built in SD card slot (rather than the available dongle) and a touch version of iPhoto. I think a lot of people who the iPad is aimed at would have liked that.