I know its far too late to be discussing this, but I have been very excited about the Pi since I first read about it ages ago, and now that its nearly here, I thought I'd give some thought to the things I might want to do with them.
So I decided to set up a VM with a similar Linux environment and started to play around with it. What I discovered was very disappointing indeed. With only 256MB of RAM, the system was not usable for anything but the most basic of tasks. By the time the system was booted, there was about 200MB of RAM for userspace code (at best, with a custom minimal kernel and minimal glibc+basesystem build), bearing in mind that this is without any GPU (the VMware GPU has dedicated memory, unlike the RPi). With the GPU there would be even less RAM available, even the smallest possible 1080p framebuffer is about 8MB, and you would need at least 2 such buffers to pageflip.
I'm curious as to what the RPi folks envision people will do with this system? I found it unable to run even simple Python programs for solving the project Euler problems. (Python3, but I don't think Python2 is much less RAM hungry). Trying to compile anything resembling modern C++ like a handful of simple games I wrote for my nephew to play/code with resulted in the OOM killer killing cc1plus. Perhaps clang can help there, but there is no way GCC is an option with only 200MB of RAM available. I can't seriously imagine kids learning to use a cross-compiler from a real computer just to get a simple game running.
Basically, I found myself struggling to find a way to use such a small device in any way that might appeal to someone wishing to learn more about computers. I had hoped to buy several, and give one to my nephew to play with and (hopefully) learn programming. But from everything my experience with the tiny VM has taught me, I might be better off simply buying a regular computer so that I can shove at least 2GB of RAM into it. It just doesn't seem like its worth sacrificing all the nice programming languages, tools, compilers and IDEs just to save a few MB of RAM. Not when 8GB is around £30. Even my phone has 1GB of RAM and its quite old already
Sadly, despite my initial high hopes for this project, I think I will skip the RPi and just buy him a nice regular PC and teach him to use virtual machines to experiment. Maybe the RPi will find its niche with hardware hackers looking for something more capable than an Arduino.