Yep. Both my UA flights last weekend featured channel 9. The captain on my return flight to DEN mentioned that it was available at least 3 times before we took off.
I've only flown a UA flight twice in the last 2 years where it wasn't on. The first one was a 737 flight where the captain didn't want it on. The other was a 747 flight that the IE was broken.
I noticed last week that I was 1 of 2 people on a full 737-300 that was listening to channel 9 or other IE. Other flights recently I've been the only person listening to it. No one else in the cable had any headphones on. It seems that most people just don't care about or can't understand it. That's probably why other airlines won't do anything similiar. It seems there's just no interest in it from the flying public.
A noble spirit embiggens the smallest man...