Rear wheel sideways "play"

as someone who has a hub in which has sideways play I can advocate taking the hub apart, cleaning it all up, repacking the bearings and greasing that baby up!

for the long term good of your wheel it is worth it, though if you have warranty just get a new set as your bearing racers may be knackered and it is frustrating if you are fiddling round tightening or loosening your hub cones every time you take your wheel off as that is what happened to me.

So I took the wheel apart, cleaned the axle, bearings and cups, regreased the cups and put the bearings back in. Then used the spanners to exactly tighten the cones on to the right level, and to tighten the lockring hard against the cone. All seemed good, but when setting the chain tension I took the wheel on/off a couple of times, and noticed that the cone was loose again with a bit of "play". Suspect it is from when I am tightening/loosening the axle bolts that this happens. I held the cone in place with the wrench the final time and it seems fine now.
Jimbo - it sounds similar to your situation with having to muck about with the cones when you take the wheel off, what part exactly do you mean may be worn out - I didn't see any bearings racers as I understand the term?