As a computer programmer I vastly prefer network approaches like Cat-5/6 over proprietary or new cabling standards. That said, I think the reason that stuff like HDMI/Display Port/Thunderbolt/Firewire have their place is because of latency. Network protocols are great for transmitting data asap but timing is fluid and can't be counted on. Add-ons to the protocol like QOS(quality of service) attempt to lower the latency for apps like VOIP and video conferencing but they're not perfect.
In summation, it's not all about the bandwidth, it's also about the timing. Think about how we tweak our projectors to get the lip sync correct, or play video games successfully.
Not everything is about A/V. Thunderbolt has it's place but nowhere near our a/v racks for the near future. I doubt that active tech is necessary for HDMI 4a stuff. I could see it being mandatory for 4K projectors but at that point, we are spending a ton on the display device and the cable will be the least of our worries.
One interesting (to me) thing about the Ars Technica article is the idea that the active chips mean that different transports like optical could be used in the cable with no change in connector. Kind of an optical balun built into the spec. That's pretty cool. I envision an active cable that allows a slim hdmi-like cable to reach 50 ft with complete compatibility.