There is, however, much less of it.
Before, at its worst, it was HOLY SHIT THE FRONT END IS SELF-DESTRUCTING but now it's more like "Damn, WTF is with that shimmy?" To the consternation of other drivers, I rolled down the highway in the right lane varying my speed between 52 and 59 MPH, and found that the worst of the shimmy was right around 53-54, and while it's annoying, it's within acceptable limits. It no longer feels as if the front end is going to tear itself apart, which is a huge improvement.
I have to believe that once I can replace the driver's side hub, it'll be even further reduced. I'm looking forward to that; and if the driver's side wheel U-joint needs replacing too, so be it. I might make that a priority for my first paycheck from the new job, in fact, because I am very encouraged by the magnitude of the improvement to the Jeep's driving characteristics.
As for tightening the hub nut? Putting the truck in 4WD locked the wheel and let me put enough torque on it to tighten the nut if there had been any room left to tighten it. I leaned on the breaker bar and saw it flexing--and by a good amount!--and that nut didn't move; I figured, therefore, that there is enough torque on it. (The breaker bar flexed enough that I was worried it would break if I put my full weight on it.)
...and when I do the driver's side, I now know that I don't have to go through the laborous process of removing the tire, removing the hub cap, remounting the tire, putting it on the ground, loosening hub nut--all I have to do is put 'er in 4WD and that'll do it. (As long as the other tire on the axle is on the ground, of course.)
Before winter I'll want to check the rest of the U-joints on the truck, of course; they all have 122,000 miles on them and if one failed, it's a good bet that more are going to. At about $10-$15 each it's not going to break the bank to replace the ones that are crunchy, and the retaining u-bolts for them are similarly inexpensive.
That, however, is for another time. Right now I have some house cleaning to do.
Incidentally, I'm trying to figure out when I last replaced the steering damper, because I'm thinking it was a "limited lifetime warranty" part and I might as well replace it now, as that'll help with the shimmy. Problem is, I didn't note it in the Jeep's maintenance log, and I don't remember when I did it. I commented on it here at the Fungus but can't find the post because none of the search engines index LiveJournal any longer. Argh etc.