I always find broadcast standards, BBC or anywhere, any country, any client to be funny. Sure they need a baseline, but when it comes to news coverage or documentary production if it suits them or the footage is unique or newsworthy, they'll accept footage from anything, including a smart phone.
We all see it all the time, shaky busted up footage of some reporter covering an event and If it's advertising they all accept anything as long as the client is paying.
But all of this is the dumbed down version and none of us aspire to shoot dumbed down, we aspire to shoot professionally and one thing that is missing in all of these standards is focus and lighting.
Nothing will make footage look better than professional lighting and camera movement, regardless of the capture device. That's why SMALL cinema/tv production crews are twenty five to 50 people.
I agree with both Bern and Sareesh.
Quality at the time of capture makes a huge difference up and down the chain. You can't really get rid of moire or artifacts properly with any program, though quality can be defined in a lot of ways.
But quality of the output is more than just the file size, bit depth, bit rate, or compression, it's a combination of all of them, with (IMO) more heavily weighted towards capture bit depth and sharpness.
If you want to do your own test, take a professional still of the same motion scene and put the still in your editorial system at around 2500 pixels across. Then look at it on a broadcast monitor compared to the motion footage and the still will usually look much better regardless of how your compress and downsize later.
You can do you own faux broadcast test, put a a video in m4v, in any size from 480 to 720 on the short side and play it through your apple TV on your home broadcast monitor. Compared to what the cable and satellite companies stream at 1080i usually the wireless apple TV footage looks as good, or better.
Regardless, as Bern says, the better your start the better you usually finish and really all of this usually comes down to budget. Everyone will mention the House episode shot on a 5D, but the crew wasn't cut down and the process was just as expensive in post.
Same with Act Of Valor, http://www.hurlbutvisuals.com/blog/2012/05/act-of-valor-workflow/
There might have been a savings in shooting with 5d's due to the multiple cameras, but just a few of those fluid heads or one panavision lens can costs more than all the cameras combined.
When you factor in the extra post work, much of which the workflow was ground breaking and make it up as you go, but they did a tremendous job and used those little cameras to the best of their abilities and don't think the BBC won't air this movie.
Anyway, this was a test I did early on with a 5d2 comparing the still capture vs. the video capture on the same exact scene and the 5d shoots soft compared to the stills. Looks good in motion, but the still frame from the motion footage is soft and does some crazy stuff like the black hole in the blowout of the practical lights in the background, where the still image of the same scene is much sharper with less issues.http://ishotit.com/rundsmc.jpg