I don't know anything about it, only that it sounds like something that absorbs an unlimited amount of your free time and allows you to implement CPUs, programmable logic, and now 3D printer models.
It is addicting, and whatever you generally spend your free time doing will be absorbed. Your interests might feign after a bit, but it won't be until you've spent a good amount of time building something.
I look at Minecraft as a good entry point for video game development. The modding community is huge, and getting larger now that Mojang is officially creating an API for modding. Also, because it is so transparent; the original map was nested folders (which is where converting to a 3D printer is so 'easy'). Logic-wise, its not built to make processors, the logic is slow. The aforementioned book would be a better suitable candidate for it.
It's actually a pretty good game for engineers. Also, it rewards you for having basic knowledge of digital design. Here's a hidden door I made using pistons which were just added to the game.
I think the main appeal is that it's basically a new take on classic Lego bricks. I turn off the monsters and just explore, and build... and I've easily gotten my money's worth from that alone.
But then again... I really liked Lego bricks as a child. If you weren't into that then it might not be the game for you.
If you want to "[...]implement CPUs, programmable logic[...]" I would rather go with "The Elements of Computing Systems" [0].
On the other hand, if you are into gaming and want to experience a sandbox building game with a huge, albeit rather premature, community and lot of modding going on, give it a try, it is about 15 €. [1]
It depends on the game, but simulation games can be good for learning/honing the meta-skill of systems thinking, imo (in the sense of http://en.wikipedia.org/wiki/Systems_thinking).
I personally avoid Minecraft because I feel some games are somewhat productive, and that Minecraft is not one of them.
I get the impression a very large part of Minecraft is mindless worker-ant operations. Compared to, say, Portal, I feel my time is better spent with the latter- even though neither produce a tangible product or any apparent immediate benefit. (Not to mention the fact that Portal has an ending, instead of going forever)
It depends on you. Personally I play with it sometimes, but for me there is no danger of addiction.
It's a fun and creative game, even relaxing. However, sometime in the future there will be an adventure mode with NPC and a better fighting system, so it might become TOO fun for someone.
In the end, however, it depends on your personality.
I don't know anything about it, only that it sounds like something that absorbs an unlimited amount of your free time and allows you to implement CPUs, programmable logic, and now 3D printer models.