You can pretty much count on two things in this timeslot: 1) Criminal Minds dominates the fourth quarter and 2) American Idol dominates the first half of the calendar year. But Law & Order: SVU may have something to say about that this season.
ABC: The alphabet started off in fall '06 with the Lost "mini-season" of six episodes, then a hiatus. The time-period filler during Lost's absence was supposed to be limited-run drama Day Break but its ratings were so bad that it didn't last to anywhere near the end of the Lost hiatus and gave way to the second half of a comedy block. Among the comedies that aired in the 9:00 hour were Knights of Prosperity, In Case of Emergency, and According to Jim, but by April results were so dire that ABC brought in repeats of Lost to try to help the originals which the net decided during the hiatus to move to 10:00. With Wednesday staple Lost pushed to midseason for '07-'08 the net went with three new dramas anchored in the 9:00 hour by the successful Grey's Anatomy spinoff Private Practice. The writer's strike cut the dramas' rookie season off so Supernanny filled in at 9:00 for the rest of the season. Practice returned for fall '08 to diminished results but got a reprieve when it was moved to Thursday after its mother show. Lost came back to Wednesday for midseason of '08-'09. This fall it's back to comedies with wonderfully-reviewed Modern Family and Courteney Cox-led Cougar Town. Cox's show will interestingly be airing in the same timeslot as her hubby's In Case of Emergency from almost three years earlier.
CBS: Criminal Minds debuted in this timeslot for CBS in fall '05 and has remained a consistent success ever since in the face of some brutal competition. It averaged about a 3.6 in originals last season but Law & Order: SVU's arrival will be a crime drama challenge unlike anything this show has seen.
FOX: Fall '06 opened with legal drama Justice here but its lack of success saw it moved to Monday and eventually Friday. The November debut of game show The Rich List was even more disastrous, axed after just one airing. A Wednesday airing of The O.C. didn't work the next week so Fox just resorted to repeats of Bones and waited for Idol to come back. Among the shows given a post-Idol sampling in 2007 were Are You Smarter Than a 5th Grader? (outstanding retention got it a regular slot on Thursday), The Wedding Bells (moved to regular Friday slot and died), and 'Til Death (decent retention got it another season in the 8:00 hour). Fall of '08 saw a solid 4th place show in Gordon Ramsay reality effort Kitchen Nightmares, and the big post-Idol launch of 2008 was another game show in The Moment of Truth. In fall '09 came a disastrous hour of comedy including 'Til Death which somehow survived to yet another season while lead-out Do Not Disturb just saw three episodes. In early '09 a drama got the post-Idol nod, with newbie Lie to Me airing for several weeks at 9 before shifting to 8. This fall the choice is Glee, a teen dramedy that aired just one episode to rather disappointing post-Idol retention in '08-'09. Newbie Human Target is slated to get a post-Idol run in the winter.
NBC: The peacock had reality show The Biggest Loser in this timeslot for fall '06 but shipped it to Tuesday and aired Deal or No Deal for awhile before importing midseason vet Crossing Jordan to the period. It continued its struggles from earlier in the season and got the axe at season's end. Fall '07 saw the extremely successful launch of newbie The Bionic Woman but it'd run out of steam within a couple months and was replaced by Deal or No Deal and eventually second runs of the now-on-USA Law & Order: CI. For fall '08 the plan was to use the last couple weeks of America's Got Talent and then Deal or No Deal at 9 to lead into Lipstick Jungle but the night was a disaster so Jungle was shipped to Friday in favor of crime drama Life at 9 which got a back nine but didn't fare much better and in fact did even worse after Lost and American Idol entered the mix in early '09. Life wrapped up in April and was replaced by Law & Order: SVU repeats to close out the season. With the 10:00 hour out of play due to Jay Leno's show NBC is moving longtime Tuesday tentpole Law & Order: SVU down to the slot for fall of '09. SVU's been so big in part because of CBS' problems in that Tuesday 10:00 hour but it took a hit from Without a Trace showing up there last year and Criminal Minds should be an even more potent foe.
CW: One of the most plum slots on the CW due to the America's Next Top Model lead-in has been unable to make anything stick. First it was WB import One Tree Hill in fall and winter of '06-'07, then repeats of Tuesday reality show Pussycat Dolls Present. For fall '07 it was the launch of new drama Gossip Girl but its results were mediocre and it was moved to Monday by spring in favor of another season of the Pussycat Dolls show, this time in originals, and the opening weeks of eventual summer reality effort Farmer Wants a Wife. In fall '08 the net started out with repeats of newbie 90210 but in late October debuted reality dud Stylista. The net could not find any original programming to put after ANTM in the entire first half of '09 so it was 90210 repeats the whole way, posting downright embarrassing retention percentages. There's another new drama getting the slot this fall, but it's actually an original in The Beautiful Life: TBL. Thematically, a modeling drama is about as compatible with a modeling reality show as you can get.
Cable Notables: Bravo's powerhouse reality show Top Chef will be a factor. Syfy tentpole Ghost Hunters will also bring original episodes to the table.