President Obama will deliver the state of the Union Address on January 27 at 9pm and you can count on ABC, CBS, FOX and NBC carrying it.
Though schedule changes haven't been announced yet, originally FOX had Human Target scheduled at 8pm and American Idol at 9pm. In order to preserve the Idol schedule, look for Idol to move to 8pm for the night.
Human Target has had some bad luck with the schedule. First, FOX was initially scheduled to have the late football game leading into Human Target's premiere event last night. The NFL's scheduling and the teams involved didn't work out for FOX though.
NBC will likely leave Mercy at 8pm and preempt Law & Order: SVU and The Jay Leno Show. I'd guess ABC will leave Scrubs and The Middle between 8pm-9pm and preempt Modern Family, Cougar Town and Ugly Betty.
CBS already had a night of repeats scheduled for January 27.