In sharp contrast to Thursday night, where the broadcast networks bring out their heavyweights, Friday night is reserved in most cases for a broadcaster's misfit shows. They're not dead yet or they'd be on Saturday, but they aren't deemed strong enough to put on any night that really matters.
The exception to that Friday broadcast programming rule is CBS, which has in the past fielded two hours of slightly below average (for the network as a whole) ratings performers. This season, they've added Medium, which was cast off by NBC, and look to have their strongest Friday line up in several years.
The shows are each misfits in their own "special" ways, Ugly Betty is airing the episodes it needed to produce for syndication minimums, benefiting the Disney empire overall. 'Til Death, was bad enough to be pulled after 5 episodes last season, but a reportedly "give away" licensing deal by Sony Pictures Television to get it to syndication has resurrected it. Law & Order is here to achieve it's 20th season and then drift into the sunset. I think Southland's renewal was realized to be a mistake soon after its announcement, and it's perhaps thought to be either too expensive or too much of a come down to *start* it off on Saturday night this season. Enough has been written already about Dollhouse's low ratings and its surprising renewal. Since Fox had no other half hour free anywhere on its schedule for a non-animated show, Brothers gets stuck in front of 'Til Death. And while Smallville is anything but ratings challenged (at least for the CW), it doesn't fit with the CW's "all young women, all the time" demo target, so off it went to Friday. Such are the tales of the Friday misfits.
Below are the hourly lineups, including each shows 18-49 demo rating average (which includes in-slot repeats) from the 2008-9 season as well as my guesses for the fall nightly overall results.
Supernanny (ABC), 1.7 18-49 demo rating
Ghost Whisperer (CBS), 2.4 18-49 demo rating
Smallville (CW), 1.4 demo rating (on Thursday last season)
Brothers (Fox), New
Law & Order(NBC), 2.1 demo rating (on Wednesday last season)
'Til Death (Fox), 1.8 demo rating (on Wednesday last season, just 5 non-repeat episodes)
Ugly Betty (ABC), 2.3 demo rating (on Thursday last season)
Medium (CBS) 2.4 demo rating (on NBC Monday last season)
America's Next Top Model Repeats (CW) 0.6 demo rating (last fall's repeats on Fridays and Sundays)
Dollhouse (Fox), 1.5 demo rating
Southland (NBC), 2.4 demo rating (Thursday last season)
20/20 (ABC), 1.9 demo rating
Numb3rs(CBS), 2.1 demo rating
The Jay Leno Show (NBC), New, Fall 2009 Tonight Show averaged about a 1.4-1.5 demo rating
These posts are getting to be a broken record, but it's hard not to imagine CBS dominating Fridays. They typically won the night last season, and Medium is a net positive. Second place looks to be a battle between NBC and ABC that I think NBC will likely win. Leno has his easiest competition of the week and should do relatively well.
Fox looks to be well back in 4th, but since their Fridays last season were so screwed up, season to season comparisons may not be that bad. The CW will see a big increase on Fridays, since Smallville, their best 18-49 demo show last season, will do far better than The Game and Everybody Hates Chris that it replaces.
Note: I make all my guesses completely unburdened by having read any reviews of any of the new shows, having seen any of the pilots, or knowing any more than the most casual details of their subject matter. Does that make mine better or worse than the typical TV writer which focuses almost solely on those? Your mileage may vary.
Fox caveat: Regardless of their other shows, the outcome of the major league baseball playoffs can make or break Fox's fall averages. If they get long series with good matchups their overall season averages benefit tremendously. If they get short series with bad matchups, they'll suffer.