Very true, handling accessibility issues is a challenge when using icon fonts. In certain browsers, the ARIA specifications suggest you could do something like

  <button aria-label="Close">X</button>

to deal with screen readers to an extent. There's also the (pretty much completely unsupported) ACSS property

  {speak: none;}

in conjunction with

  <aria-hidden="true">

and then describe the icon with an offscreen span, pretty much as described here: http://css-tricks.com/html-for-icon-font-usage/#jump-alone. Still not even close to a good solution, though. If you have any insight into better handling icon fonts, I'd love to know.