I have a G1G1 OLPC 1.0 that we bought in a fit of enthusiasm back when they first came out. These days, it sits untouched.
The greatest highlight on the device was the great screen. I certainly hope Pixel Qi finally starts shipping in volume at a reasonable price. The eReader mode looks great, and I'm sure they've improved in the intervening time. The tough, splashproof hardware was nice too.
Unfortunately, lowlights abounded: It was incredibly slow. It took forever to boot and applications starting took way too long to start. The keyboard was atrocious (even kids are better with a full-sized keyboard). The touchpad was wonky. The software only made sense if you were with a whole classroom full of other OLPCs (at the university I work at, we had a couple of get-togethers, and we managed to do a little bit of the "sharing" stuff with it). It was cool when it worked, but hard to get to work. Documentation wasn't great and even with a collaborative effort by 10 or so IT folks, we couldn't get things to work consistently.
Even with the enthusiasm most of us had for the idea, it was hard to get enthusiastic about developing for it as you couldn't do much out of the box and those of us with the expertise to program found it uncomfortable to work on. Yeah, you could plug in a keyboard an mouse, but still, it wasn't a great experience.
I also tried a few of the alternate faster-booting linux variants on it, and those improved the software, but the keyboard/touchpad still made it unpleasant to work on.
I know, I know. This thing is way beyond what a kid in abject poverty in a developing nation would have otherwise, but if people with expertise in computers can't get it to work and find it uncomfortable to work on, how would the expect to get developers to work on it?
Then the later issues with Classmate competition, XP, management, delivery, etc all compounded apon the initial hardware design issues....
I thought it was a great project, but not so much that I actually wanted to use the device after I got one. I tried for a long while...