I waited two weeks into 2012 to give the system ample time to catch up but...
What I understand from Jan's posts is that Google Earth performs a daily pull of all new and approved 360s on 360cities. I'm not certain whether that means "never before seen on GE" (only just uploaded and approved on 360s) or "any modified 360" (possibly swapped and re-approved).
Case 1: Brand new 360 all around (only just posted and approved)
My limited experience is that "never before seen on GE" are indeed pulled into GE almost immediately after approval on 360cities. I've only had one or two cases of this lately, but I should be able to test this in a few days when my newest 360s are approved. My new cases, unfortunately, were loaded during our recent problems and so are corrupted on GE but they did load fast! So, for the first appearance ever on GE, the system does seem to update rapidly (perhaps the next day after approval).
Case 2: Existing 360 that was swapped and reapproved
For the month or so preceding the holidays, I went through all my old 360s and re-rendered them using my latest software and the techniques I've picked up over the last year or so. I'd say I swapped over half of my old 360s with new renderings. When I started, we didn't yet have the daily GE update, but eventually by the end of my redo, we did have the GE daily update.
What I noticed with Case 2 was that the thumbnails in GE would update, but that the sphere itself would not. By "thumbnail" I mean the initial GE pop-up that gives the flat equirectangular preview of the 360 before you decide to enter its sphere. In all cases, this thumbnail was updated daily after reapproval on 360cities.
However, the spherical view itself was not updated. I even logged out of GE (you can read the help for how to do this) and wiped my local GE cache on several occasions just to make sure my local GE wasn't serving up a sphere cached locally. Nope, the "old" sphere seemed to be coming from GE despite the thumbnail being updated.
I suspect that GE has a backend caching system that currently does NOT update daily. I could believe that this is a compromise on their part between service and computational/storage expense. They'll spend the time to process Case 1 (never before seen on GE) daily but not Case 2 (swapped). Case 2 seems to update on a slower schedule.
Before the holidays, none of my swapped and approved 360s had been updated on GE (the thumbnails: yes, the spheres: no). In the week between December 23 and January 1, when I understood Jan to say that the whole GE process was on hold, all of my updated 360s were updated on GE, this time in their spheres.
In early January, the first few updated 360s that I checked were corrupt as others have described - patchy nadir with discontinuities along longitudinal lines. I opted to wait to see if the daily updates would fix the problem. But they have not. I'd say more than half my 360s in GE now have the image corruption problem.
FYI, I also noticed that little time stamp update issue that others have seen - some of my panos showing new modification dates for times that I didn't touch them. I assumed this was an effort on 360cities's part to trigger an update at GE.
Also, people should remember to turn off terrain in GE (Tools->Options->3d View->Show Terrain) before they report nadir problems. I find that the terrain often comes into a 360 sphere if you have it turned on and looks similar to the patchy nadir problems that we're seeing. If the problem goes away when you turn off Terrain, you don't have the nadir problem we're talking about.