A/C Compressor Noise

[Zilverado]

Just got back from another 2 week camping vacation - ahhhh... Truck did quite well (as usual) pulling our little camper, but the A/C compressor is starting to give me a little concern.

The A/C works quite well, despite the truck being parked (and not driven) out in the cold all of last winter. But the compressor is starting to "whine" and "groan" more than I like. It's always had a sound to it, which I have assumed is "normal", but it's definietly getting louder - - very noticable at idle. And, the compressor pulley/clutch assembly is greasy/oily, and flinging this oil onto adjacent parts and the underside of the hood.

I have attached a couple of photos of the compressor and the underside of the hood. I had to lighten the compressor photo to show the oil stain on the power steering hose below, but the phot still clearly shows the greasy build-up on the compressor pulley.

So, any suggestions on this? Is this the early stages of compressor failure? If so, that would be too bad, since it still cools so well...