Well, you have to combine just two of these features to leave Nim in a very small company of languages, mostly developed in the last decade. Good performance and meta-programming ("run regular code at compile time") used to be found at the opposite ends of the programming languages spectrum and Nim is unifying them in a single package - that's what people are excited about.
The Nim compiler offers a set of tools intended for use in IDEs ant text-editors that help with this. Besides the style insensitive grep, there are also a compiler-assisted "go to definition" and "list references" commands.
I'm still waiting for the day when the JS community will discover tup [1]. Tup's greatest strength is that is can discover build dependencies automatically by file I/O monitoring in any kind of compiler or build script.
Many source formats eventually gain the capability to include other files (e.g. jade partials) or reference them in other ways (e.g. you can check the size of an image while you are generating a Sprite CSS fragments) as part of the build process and this is where Grunt or Gulp or any other naive build system will fail immediately. Specialized build systems can handle the dependency checking for particular build targets (e.g. Cmake for C++), but tup makes it extremely easy to have proper minimal re-builds with any kind of compiler.
There is also an automatic re-build mode that's triggered as soon as you save the source file in the editor and it's a joy to use in web projects.