Okay, I did this from memory, so please don't stone me if I missed something. What to expect from the Fall 2012 tour (I expect zero changes for the Aug/Sep shows!)
"TOOM" really was the last album where new songs affected the set structure immediately, so we shouldn't expect miracles, however, "TOOM" came after a seven year silence (and considering the lack of airplay for the "TTL" songs, it's been six years since he put out an album that got played live), he was very keen to promote it and it signaled a shift in sound, thus it made sense to play lots of new songs in prominent slots. All this *could* (Fingers crossed!) apply for "Tempest" as well. But just don't get your hopes up too high.
For "TOOM"
Roughly four new songs where played in a 15/16 song set on the first full tour after the album release (Fall 1997). This was the first new material in seven years and the "Red Sky" songs had pretty much vanished from the setlist by 1991, so the new stuff mostly replaced "Oldies".
Unlike the albums that followed, the "TOOM" songs immediately occupied certain slots in the setlist, some of them quite prominent (two in the first six-song electric set), "Til I Fell In Love With You" as the first song in the second electric set, not much later it was used as the main set closer.
With "Love Sick", a new song was always performed in the encore, a trend that has continued with all subsequent albums.
Less than half a year after the release, there were as many as three new songs in the opening six-song electric set and up to six songs in total in a 16 song set.
It took years before a "TOOM" song became the opening number, though.
10 out of 11 songs were played live, nine of them often or very often, and "Dirt Road Blues" was used in "M&A".
For "L&T":
Roughly 4-5 new song per night on the first (US Fall) tour, albeit in a long 20 song set, mostly replaced any "TOOM" songs that used to be in the set before.
None of the new songs were played in crucial spots such as first three, last, first encore etc. The first new song came at #5.
One of the new songs ("Honest With me") was played in the encore.
One years after the album's release (2002 Fall tour), songs from "L&T" were used as the opener (sometimes) and main set closer (always).
All of the songs were played live. Many, many, many times.
For "MT":
On the first (Fall 2006) tour after the release, relatively few new songs were played at first, the number rapidly progressed as the tour went on, though. The set was shorter (around 16 songs) though, so percentage was about the same as above.
By the end of the first tour, one new song was the first (of a two song) encore, and another one was used at the set opener a few times. "TOTM" eventually became a set closer on later tours, although not for long.
Key songs from the previous album, like the closing "Summer Days", initially stayed where they were before.
All songs were played live, most of them to death. ("Somebody Baby" had only been played once, in 1990

)
For "TTL":
On the first tour after the release (Summer 2009) usually only one or two songs were played, this was mostly a co-headlining tour, though. There were a number of nights with three new songs in a 14 song set, making the percentage not drastically different compared to previous albums.
"Jolene" was played in the encore (much like "love Sick", "Honest With Me" and "Thunder" before.)
Apart from that, the songs never occupied crucial slots in the setlist, neither on the first tour nor later.
Key songs from the previous two albums stayed where they were, often outnumbering the "TTL" songs on the setlists.
It should be noted though that the number of "TTL" songs was considerably higher during the Fall 2009 tour, with 4-5 songs on average, matching the average from previous albums.
8 of the 10 songs were played live, but only two made it into heavy rotation, the lowest number of original songs since "Red Sky" in 1990.