I had the identical problem, except I knew it was coming after having miked the disks and finding they were near minimums. The brake wear light is on for a reason (and not a good one).
This weekend I replaced all four disks, all eight pads, both sensors and the brake fluid. The pads were down to about .15" (4mm), the disks were at minimums and the sensors were touching the disks and were being ground down. I believe you are in the same situation. If you have driven only a few hundred miles since the wear light came on you are safe for a few hundred more, BUT the disks and pads won't last much longer, so get used to the idea that they have to be replaced SOON. The brakes are the most important part on your car. I used OEM-equivalent parts from Bavarian Autosport for about $360 (includes new disk retaining screws and bleed screw caps). Brake fluid DOES go bad, so if you haven't replaced it in a while, do that, too.