I was doing some work on the bike the other day and had it up on a rear stand. Long story short, I put it in first gear and pulled the clutch in all the way and the rear tire was spinning at a pretty decent speed. Its not enough to notice while riding though. Does this mean the clutch is going out?

This is normal.

^^^ what he said.

If you want a real simple example of this, put a sponge in the kitchen sink full of water. Then put 2 fingers in the water and move them past the sponge. The sponge moves eventhough you didn't touch it. Same principal here.