Wheel bearings?

[justinstagl]

I took my wheels off this weekend to inspect the brakes, suspension, and wheel bearings. The brakes were in decent shape, and the suspension looked ok(except for some old bushings), but the rear wheel bearings have me concerned. The wheel hubs seem to wiggle in and out of the bearings(I think). There is no side to side play, or wobble that I can feel, so I figured I should ask someone more knowledgeable. Also, where it is wiggling seems to be wet(oily?), and Im not sure if I should be concerned about it. A picture is worth a thousand words so I uploaded a ~10 second video:

http://youtu.be/ZCeNR8wFifc

If you could check it out and let me know what you think I would appreciate it.