Looks like you have a spike keiki (new baby orchid)!

You may choose to leave it on the plant or remove it. If your plant is healthy enough (good root system, etc.) then leaving the keiki on the mother plant shouldn't affect the mother plant too much. I would leave the keiki attached until it has at least 3 roots 3-4 inches long.

Good advice goldster. If the leaves start to get limp, then cut the spike at the base. But your plant looks strong. When you see the 3 roots cut the spike several inches below the new plant. When potting it cut the spike a little more so the plant fits inside the pot with the spike touching the bottom of the pot. This way the new plant can get nutrition from the old spike. It also provides an anchor for the plant. Eventually the old spike will turn into dust...

That is so neat, I had no idea they could do that.