Starting yesterday evening I noticed that when I do things that exercise the new "blue" background progress indicator - such as opening/saving a file, or doing a 3D rendering - that the progress indicator remains. What I was doing at the time when this first appeared was 3D rendering, because the first time I noticed it was when a rendering finished but left the 0% indicator on screen as shown here:
After that, even if a document was opened, the blue bar just stayed there:
This was repeatable across Photoshop sessions (i.e., I could close and re-open Photoshop and reproduce this behavior).
It occurred to me that this field is supposed to be replaced by status info after the document opens, so I checked to see what the status was set to. Turns out it was set to nothing in the list, implying preference corruption, albeit minor.
So to see if it would clear up the problem I set it to Document Dimensions, which is normally what I prefer, and voila, now it works as expected - showing only the progress indicator during saves.
After choosing the setting shown above, now the problem is gone - even across sessions. A subsequent attempt to set it to Save Progress results in it reverting to Document Dimensions by itself anyway. There seems to be no way to "manually" create the problem I illustrated at the top of this post.
I neglected to grab a copy of my preferences file before changing the setting, but I realized my nightly backup snagged a copy last night, so I did have one on hand, and sure enough, restoring last night's backup copy of Adobe Photoshop X64 CS6 Prefs.psp to service returns the problem.
If anyone at Adobe is interested, I'll be happy to send you a copy of my 64 bit Ps CS6 prefs file which which this issue can be reproduced. Please let me know.