Video of CraftStudio in action: http://www.youtube.com/watch?v=r1QbJO3y_O0
Hacker News thread from yesterday: http://news.ycombinator.com/item?id=3751455
Clones have also started to appear but it's still small indie companies making them, meaning it'll take time before many are at the same level as Minecraft.
However, the bigger companies do seem to be paying attention (an EA bigwig spoke about Minecraft in a Gamasutra piece the other day [1], though he was saying fairly obvious things), so it'll be interesting to see what the genre's like in 5-10 years' time.
[1] http://www.gamasutra.com/view/news/167137/Minecrafts_future_...
I'm surprised it hasn't spawned "sandbox games"
as a completely separate and significant genre
Maybe you haven't noticed, but "minecraft-like" is a a burgeoning young genre - every week I see a new one on the /r/gamedev subreddit or tigsource forums.And there are already a dozen or so commercially successful ones on steam and XBLIG.