Is my belt tentioner going south?

4 cylinder, 2004 Camry LE with 117,000 miles.

I was looking into my wife's complaint about a weird sound coming from the passenger side front but did not hear anything. So I popped the hood and looked at my serpentine belt:

https://plus.google.com/photos/11305...31095126733073 (https://plus.google.com/photos/113054849876116872599/albums/5817131095126733073)

I do not remember seeing this before.

I can also see the same pattern on both pulleys that the flat side of the belt rides on.

I replaced the water pump 20,000 miles ago. So I removed the belt but did not feel any play in the pulley.

I started the car and using mechanics stethoscope checked the sound near every pulley I could reach. The belt tentioner sounded much louder, plus the sound was not even and I heard some light knocks.

Did anybody have this problem?

Regards,

Sam