My Wedge keyboard has also stopped working. It has been fine for the last year until I upgraded IOS to 7.1.2 and then it stopped working. I tested it on an HP laptop and it is working fine. If I was a cynical person at all I could read something into this coincident. My Apple still works fine but I prefer the MS one because it has a neat support for the ipad, this also provides physical protection and finally is smaller. No point in suggesting I check the MS item because I have and it didn't work.
The keyboard and the ipad connected like they were made for each other when I initially paired them up.
So thanks Apple.