Not overpowered at all. Comparatively to Intelligent Blademaster (FRPG) this feat allows a to-hit stat (dex) be substituted for basic attacks. That is almost exactly what Intelligent Blademaster does, however, Intelligent Blademaster limits it to swordmages and adds a second weapon group.
Your feat opens the option to everyone and limits it to a single weapon group. Seems fair to me.
The only change I would make would be to add the rogue class to the prerequisites and drop the Dex requirement.