From cat5 specifications:

50v x 4 circuits x 577mA = 115W maximum over short runs.

100Meters DC resistance < 18 Ohms giving a maximum loss of 10v, better for higher quality cable.

40v x 4 circuits x 577mA = 92W over 100M

I think cat6a has a higher current rating and lower resistance so would be better, although I'm not sure about the voltage.

In that respect I do hope that they can make this standard in 6 weeks. I might want to buy a new TV after that date.

I can see a market for RJ45 > HDMI Adapters.