I really don't understand the wave of alarmist posts on the 'end of a tinkering era'. Today, we have more communities and devices for tinkering than we've ever had. Magazines like Make, sites like Hack-a-day, platforms like Arduino, and
countless open source projects that are simply there to be messed with, and one device that comes out with a (probably) justified need to be locked down, and everyone raises panic? If I ever have the desire to mess with anything technological today, I can literally get my hands on anything, from affordable FPGA boards with great I/O, to open mobile devices, to even RF hacking! (GNU Radio's great.)
The iPad will never harm anyone's ability to tinker with technology that want to. There will always be platforms that are open by design and always be platforms that have been rooted/hacked/jailbroken/etc. Being a geek/hacker today is far more socially acceptable and wide-spread than it was in the 80s. I'd even argue that it is doing much more to advance the technology than a completely open device like OpenMoko. Completely open devices are rarely better designed than their commercial counterparts. They don't inspire complete neophytes ("I have to do what just to get a decent resolution?"), they don't push boundaries -- they only appeal to people who are already waist-deep in tinkering.
Frankly, if anything, all of this comes off as elitist. God forbid people get their hands on technology that doesn't have a steep learning curve or require you to write BASIC to be useful. Well-designed products that have a lot of concentrated money (and more importantly, talent) inspire people much more so than completely open systems. I think of them as (and please pardon the extremely hyperbolic analogy) well-polished, completed works of art. They won't teach you how to paint or let you alter them, but they'll show you what's possible with the canvas and advance the art.
I'm actually now thinking back to a discussion with a friend of mine, who's a collector of 60's-era oscilloscopes. He was raving about them as being the pinnacle of electronics engineering. Not only were these scopes beautifully designed, but their manuals detailed everything about them, how they worked, what tricks they used to function, what micro-components they used. Their documentation authors really wanted you to understand exactly what made it function. Maybe that's the ideal, but I still believe that beautifully-designed products, even closed, further the state of hacking far far more than completely open platforms. If you don't believe in it, don't buy it.
If you believe they're a step in the wrong direction for open platforms, make another blog post tomorrow when you have less open platforms, less hobbyist projects, less educational materials, and less hobbyist communities than yesterday.