Scratch

I think it's a really cool idea. People that are advanced in scripting in various computer languages could make their own blocks, and upload them to the website for other people to use!

And if that wouldn't work, there could be an "execute script" block (Like in Game Maker). You can choose the scripting language you would like to use (Ex: Lua, Javascript, C++, etc.) and make your own scripts. I personally would like Lua as a choice, because it's really simple. If you've ever played the game ROBLOX, you'll see how you can make your own scripts to customize the level.

An example of an execute script block would be:

<when green flag clicked>
<execute script [v]> --The 'v' is a drop-down text box where you can type in your script.
|Type: Lua | --(You can change that)
Scratch.Sprite1.x position = 35
wait(3)
Scratch.Sprite3:clone()

That is pretty much what I mean. I will make an image later if you don't understand