This is a feature I would love to see added. I'm not an expert on diff tools, but I use WinMerge quite a bit - a compromise between its features and ST's design philosophies would be really nice to see.

I think it's important to keep ST as feature-minimal as possible, but if notepad++ has a built-in diff tool I think it's okay to add one ..

Features like this are best left to plugins. In my darker moments I want stuff like this, but then I remember that it makes me a lazy programmer, and it adds bloat to an otherwise, err...sublime...tool.

I don't want sublimetext to ever tell me how my code works, because
A) it doesn't know

B) I should be able to figure that out, or else what the hell am I doing?

On the other hand, I want to be able to run this program everywhere I need to, which means not having it manage gigantic amounts of superfluous information.