Update 3:25p: a big fat TOLDJA! coming soon from Nikki Finke! James Hibberd reports NBC has ordered 3 more episodes of Trauma.
Update 3:50p: Thanks to E! Online/Watch With Kristen's Jennifer Godwin for alerting me that it's 3 additional hours, not four.
We'll probably have to wait for the mid-season schedule announcements or some official word from NBC, but Nikki Finke is reporting that NBC will order additional episodes of Trauma (and that all the reports on blogs that it wouldn't order more episodes were wrong!).
Finke cites improving ratings as the reason more episodes will be ordered, but if the rumor is true, it seems way more likely that NBC would order additional episodes only due to lack of bench strength and desperation. The show reportedly costs a lot to make, and the recent ratings improvements have been small, rather than "wow, where did THOSE ratings come from?"
In fact, the only ratings improvements we have seen have been in preliminary numbers which, when finalized showed no ratings improvements. Monday night's Trauma scored a 1.8 adults 18-49 rating in the preliminary numbers, and a 1.8 in the finals. It's better than a 1.7, but...
Update: on the point of lack of bench strength the commenters are speculating that any additional episode order for Trauma can only mean bad things for Parenthood (though with only 3 extra hours being ordered it doesn't seem likely it has much to do with Parenthood).