It was with a bit of relief as NBC finally released its mid-season schedule... about two weeks later than promised by topper Kevin Reilly. No word on what led to the prolonged period between the intended announcement and, er, yesterday, but some rather unexpected results did manage to turn up. Let's take a look: MONDAY: NBC has kept its entire Monday night lineup intact, including the struggling Studio 60 on the Sunset Strip , which will remain at 10 pm. Many insiders had thought that the Peacock would try shifting the sinking Studio 60 in another slot, but it's staying tight for the moment, following a full season pick-up for the series, albeit at a reduced license fee. Look for a midseason drama (see below) to take over here in a few months' time. TUESDAY: Newsmagazine Dateline NBC will take over the 8 pm timeslot vacated by struggling freshman drama Friday Night Lights . Hmmm, anyone seeing shades of Reilly's announcement a little while back about programming cheap