I'm also getting the service brake light with no mileage, I took it to the local dealership, scanned the key and the service message says the brakes are 372K miles past due. I'm at 51K miles now and they were all serviced at 31K miles. The dealership offered to investigate this for $115.
I tried the reset steps listed above a few times, with no immediate changes, maybe this afternoon when I drive home from work it'll be off.
BTW - I also got a quote (if they actually need to be replaced) of $620 for the front brakes to be serviced and $620 for the rears.