I didn't come up with anything in the search, so I'll throw this out to the experience of the group.
On the way out to Ouray, the truck started showing a slight "hiccup" at about 2000RPM (+/- 200 or so). I wouldn't call it a stutter, per se. There is no noticeable RPM drop (at least on the tach), but you can feel yourself lean forward as is the brakes were momentarily engaged. The whole thing is about a second long.
On the trail, I didn't seem to have any trouble, mostly the issue seems isolated to steady throttle position on flat roads.
Nothing about the "stumble" is violent, but it is certainly noticeable, and it happened too many times to count on the way home from Ouray.
I initially thought I had some bad gas on the way to Tincup, but the fact that I went through a couple of tanks during the trip seems to rule that out. May run a little Seafoam through it just for grins.
The truck has almost 93K on it. It is a 2004 Tacoma DC, 3.4, Auto. Always Toyota parts and service intervals. Plugs are in good shape, MAF is clean. Maybe a plug wire or a coil? RPM-specific symptom makes me think it isn't fuel related, but that could be wrong.