Summary: There are 2 separate attack speed bonus stats. "Attack Speed Increased By xx%" which works fine and a duplicate of this stat that does not work that is "Increases Attack Speed by xx%".
All the complaints about specific gear are for the 2nd one. I have several pieces of equipment with atk speed bonuses, 2 of which use the "Increases Attack Speed by xx%", which does nothing on both of those pieces of gear.
Link to an image of both versions of attack speed bonus stats: http://imageshack.us/photo/my-images/443/d3atkspdbug.png/
I hope these makes it much clearer on what the bug is than all the posts complaining about specific gear, in that this isn't a gear specific issue, just a specific version of a stat issue.