As I wrote on Monday:
First and foremost, the production of electronics has a huge environmental impact. Precious and rare metals to build the gadgets, global supply chains to bring those materials to manufacturers (and bring those gadgets to market), and the energy used during their lifetime are the beginning of the problem.
There is also the huge problem of end-of-life management for these gadgets. Electronics recycling is at best a nascent market -- as we write about all the time on GreenerComputing, and which we find in our annual State of Green Business report. At worst, we're throwing away far more gadgets than we should be, and neither manufacturers, retailers or governments have yet put in place a good way to collect even a fraction of what's discarded.
But the biggest problem to my way of thinking is that the tablet will just be an addition, not a replacement.
Look at the "netbook" market for cheap laptops that are designed to surf the net well -- they're often highly energy efficient, and that's a good thing, but the vast majority of netbook owners use them as a supplement to their full-sized and full-spec laptops or desktops (and their phones, e-readers, what have you), thereby multiplying the impacts per user.
I stand by this assessment. In a nutshell, the iPad is a nifty little gadget, I'm sure it will do wonders for how people engage with technology, and hopefully will give a boost to the flagging newspaper- and book-publishing industries, but it is still another resource-intensive gadget that will be an add-on rather than a replacement.
More pics below this post, but if you're interested in more wonky details, be sure to check out the live-blogs at Engadget and Gizmodo. If you're reading this, you've probably already dug into those sites, but still -- be sure to check out the pre-game chat on Gizmodo; their editors are a funny bunch of guys.