Final ratings were adjusted up slightly to a 3.3, which is still a huge drop from 4.7. 29% drop in viewers (12.12 to 8.66m).
I'm guessing it will be a heavily DVR'd show, however, regardless of how much they're pushing the "watch it live" stuff. They were advertising "20 million viewers the first week" during Castle Monday night, which means they had about +8 million views after the pilot's live airing.
I liked the 2nd episode more than the pilot, but that won't mean anything as far as retention. I don't have everyone slaved to my TV.
Next week will be interesting, first NCIS without Cote de Pablo.
(Regarding NCIS, their ratings were actually very slightly down from the season premiere, even being Ziva's last night.)
Still, I'm not sure I understand the logic of premiering any show against two competing networks' juggernauts.