Is this so bad? It seems to me that using <i> for icons has become pretty standard across many sites and you shouldn't be using the <i> tag for italics anyways - there's <em> for that now.
Using <i> for icons is a bad idea. Wait, no, it's the wrong thing to do. The <i> element still has meaning and can be used for that purpose, of which has absolutely nothing to do with icons.