As long as it still fires I wouldn't worry about it. Mine is from '08 and from what I've read some can have strikers break from excessive dry firing.
My 9mm has about 12K rounds thru it without a problem. Just regular field strip and clean after every range trip. I detail stripped it at 10K rounds and it really wasn't very dirty so I probably won't bother again.
Scroll down this link and you will find an M&P Armorer's Manual that you can download. Good to know your pistol.
page7b
Dave