To all that believe most users will understand it, you should be careful making assumptions like that. You'd be surprised how often your intuitions are wrong assuming you're designing for a large general public audience (as these tweets suggest). I have seen in a number of tests where many users didn't know the hamburger and didn't know that a magnifying glass was where you would click to search. They were expecting a field rather than just an icon. I'm not saying this means you shouldn't use these icons, but you should definitely think about it very carefully with your target audience in mind. And if possible, test it.
To all that believe most users will understand it, you should be careful making assumptions like that. You'd be surprised how often your intuitions are wrong assuming you're designing for a large general public audience (as these tweets suggest). I have seen in a number of tests where many users didn't know the hamburger and didn't know that a magnifying glass was where you would click to search. They were expecting a field rather than just an icon. I'm not saying this means you shouldn't use these icons, but you should definitely think about it very carefully with your target audience in mind. And if possible, test it.