Josh Emerson was speaking about Asset Fonts at Responsive Conf, these are my notes from his talk.
What are asset fonts? Bit like webdings but you can customise the icons. They scale well as they are vector - not just retina, any DPI. They are very good for accessibility as they zoom with text.
Why asset fonts? We've been using sprites for a while but they have issues. Fonts have distinct glyphs for each icon - much easier to manage. They will work in any browser that supports web fonts and they are text so flow well. Limited to one colour.
Can use FontForge to create them. IcoMoon is a web based service.
speak: none in CSS to prevent screen readers from reading it.
Symbolset uses ligatures to create interesting combinations. Creating your own can be done in FontForge and is a bit tricky. forecast.is is an example of this in action. Check support - IE10+