I checked my 2012 today 7500 kms pulley wobble .072 inch or 1.8 mm as I measured it
I dont own a dial test indicator but I found by clamping the pulley rim against the swing arm with a pad under to protect the paint a good measurement can be obtained between the rim and the underside of the belt guard bracket with a Vernier caliper
Then by tapping a wooden wedge in the  top side of the bracket the rim can be pushed the other way to make another measurement.
This amount of wobble seems to be normal for these bikes and the modifications above to correct it seems well worthwhile to me.
Squeaking Noise and  belt life are two good reasons

Over the weekend I did a bunch of 2 up riding with my teenage son on the back and what do you know. I certainly have pulley wobble now!
That and I did a long peel out to amuse the kid too.

Must have been the last straw...

Looks like your bushing fix is top notch Dave.  How many miles do you have on it now?

I just measured up two pulley carriers and one hub. One carried to hub combo had over .020" clearance, and one had less than .005".
I'm guessing the tighter one would be fine, and the looser one would benefit from  some love.
As luck would have it, the looser fit carrier is the one I've done a bunch of machining to (adding Drillium, changing studs to bolts, other pointless stuff).
So, I guess I'll go with the double row ball conversion DBM came up with.
Thanks to all for the smart thinking.
-Armen

Thanks to Dave and DBM for all the research and smart ideas.
A few thoughts:
I wonder if we are looking at this as the tail wagging the dog?
Part of the reason the pulley carrier is wobbling may be the loose fit of the gazzinta spacer on the axle. It seems to be a decent fit into the carrier bearing, but if it is a loose fit on the axle, the carrier can rock back and forth.
I had made a new gazzinta spacer out of some kind of hard aluminum (forgot what kind) to save a few ounces.
I'm tempted to make another with only a few thou of clearance between it's ID and the axle OD.
I ordered a double row bearing. I'll make a new left side spacer with a shoulder as DBM showed, also with the ID only lightly larger than the axle OD.
Maybe with all that, the carrier won't be able to wobble and murder the carrier bearing?

Dave,
If the carrier is wobbling, there is play somewhere. Once the bearing is toast, than that becomes the source of the wobble.
Before that, it'd have to be the clearance between the bearing and the bore in the carrier, and the inner race to the gazzinta spacer.
So, I'm going with the double wide bering, new, tighter spacers, and the left spacer shouldering into the outer part of the bearing. That should do it

Not a big deal.
The only part that hurts my feelings is that I bought and installed a new single row 2RS bearing, a new seal, and made a captive outer spacer (held in place with the seal.
Ah well.

I agree with Dave, the clearance between the axle and spacers isn't the source of the wobble.  Once you tighten up the axle nut the spacers pinch the inner race of the bearing and lock it in place.  If you do the Double Row Bearing mod, you have to make sure that the faces of the inner and outer spacers do not touch.  That way, you will be assured that the inner race is pinched.

It won't hurt to make the clearance between the spacer ID and the axle OD tighter, and it will improve concentricity between the axle and the pully OD (always nice to maintain concentricity, its all good).

I used the stock inner spacer and I modified the stock outer spacer, so concentricity should remain within factory spec.  The critical measurement is the shoulder length.  You want that to be .338" or a little less to make sure that the inner race gets pinched.

Place I ordered my wheel bearings from caries this bearing too.
http://bearingdepot.com/5305-2RS_Bearing?search=5305

I stopped in at the machine shop up the street and was told they can turn down the spacer for me no problem.
So I'm gonna go with this mod since I got wobbles.
Weird thing is my wobbling changes each day. Some days it's bad and others it's hardly there. Not sure what to make of this.