And...we now have show return dates from the Peacock. Yes, I've noticed a trend here too: Looks like the bulk of returning faves, etc. will arrive in April, just in time for May sweeps. 
Don't worry if you don't see something you love/cherish/miss-desperately below. Here's NBC's qualifier: "Specific plans for other NBC scripted series are currently being determined and
will be announced later."
Here's what we've got so far:
"My Name Is Earl" (Thursdays, 8-8:30 p.m. ET)
Resumes April 3 with one-hour episode
"30 Rock" (Thursdays, 8:30-9 p.m. ET)
Resumes April 10
"The Office" (Thursdays, 9-9:30 p.m. ET)
Resumes April 10
"Scrubs" (Thursdays, 9:30-10 p.m. ET)
Resumes April 10
"ER" (Thursdays, 10-11 p.m. ET)
Resumes April 10
"Law & Order: Special Victims Unit" (Tuesdays, 10-11 p.m. ET)
Resumes April 15
"Law & Order" (Wednesdays, 10-11 p.m. ET)
Resumes April 23