Nice idea, I would probably leave out the mining software, though. It adds unnecessary complexity (am thinking of grandma here) and im most regions even GPU mining is not profitable anymore if you factor in the cost of the GPU. Perhaps make the mining part optional for advanced users.
Somewhere I've seen a pc-on-a-stick which would be awesome to boot a linux os from for your idea, but I couldn't find it just now.
I actually thought about the idea of excluding mining software and decided against it. This Bitcoin 'starter-kit' wouldn't work for grandma anyway. Grandma has bad eyesight and can't adequately check to make sure that she is sending/receiving bitcoins to and from the correct addresses. Grandma might, if she's lucky, understand 'right-click + copy,' and that's about it.
This starter-kit would be for the 'average' computer user. Think of it like this...this product would target people within 1 standard deviation of the mean in terms of computer knowledge, like the 'bell' of a bell-curve. When I started bitcoin, I considered myself slightly above the mean in terms of computer knowledge. I had never built one nor written any complex programs, but I had spent some months in my younger days working with qbasic (yes, qbasic) and html. I know some basic commands in cmd, etc. etc. etc. Through Bitcoin, I found out it was downright easy to assemble a computer, and aside from the time it took to learn what I needed to build, tune, and optimize a functional mining rig, that part was easy too.
All the hackers and computer experts in the world know what Bitcoin is and can understand it and use it without any issue. Those like myself who have a semi-rich background in computer knowledge can understand and use it with a bit of time. Still, there are others who have basic computer knowledge but use computers on a regular basis and can understand and use Bitcoin with some real effort. These last two categories are the one's I'm targeting as I feel they will be the most likely to take the plunge.
However, I like what you said about "making mining optional for advanced users." I could make different packages for users with different levels of experience.