Lets get a few things straight here. As this author seems a bit nieve.
1. ABC and Fox are currently using 720P. Part of the reason for this decision is that the P part of the 720P makes sports action look better. The other is that in over the air signals, a 720P signal takes less Bits/Sec, and this allows them to split the channel to DT-1, DT-2 and DT-3. Then they can sell space and time on their affiliates for the additional signals. A 702P signal does limit the bandwidth allocated to DT-2 and DT-3, however, vs an SD signal on DT-1.
In general ABC O&O's (owned and operated) stations are programiing a news channel as DT-2 and a weather channel as DT-3. Note that DT-2 is an SD channel and DT-3 is a less than SD quality channel.
NBC and CBS are 1080i. This means that when they are in HD mode over the DT channel, they cannot program DT-2 or DT-3 (those would be off the air, when they are sending SD programming over DT-1, they can have DT-2 and DT-3. Generally PBS does this with their stations.
Cable takes their feeds directly from the stations, now a days, and not over the air, so can have DT-1,2,3 all the time for use on the cable channels. Comcast often enters into cross promotion ideas with the network affiliates for promoting their DT-2,3 signals on Digital cable channels.
I agree, most dramatic TV shows were produced in film. Sit-coms are often shot in tape via the 3-cam method perfected by I Love Lucy.
Film TV shows may have been edited on 35mm (4000 pixel equivalent resolution) or 16mm or super 16. Most were distributed in 16mm or super 16. Some were even shot in super 16. Super 16 does not have the same resolution, but scales well to at least 720 if not 1080. The i/p difference for Film is moot as most HD-TV's detect 2/3 film pull down, as that is a featuer of the DT stream to better use the MPEG bandwidth. Almost all TV shows on film are 24fps.
Having said all that, I am surprised how little research this columnist did for his article. He didn't even check with the engineering departments of the networks for what signal spec they are using.