This is not new & lots of others sell similar functionality Dell DRAC, HP ILO... Those usually have dedicated Ethernet ports, but generally function the same way. I've been helping our workstation guys roll out Intell vPro for remote administration of laptops & workstations. It operates in a powered down state & can do 802.1x authention to the network while the OS is powered down. So ya, there is definately an out of band processor there that can wake the system up & do remote control type stuff. It's a feature Intel is selling & marketing.
Can't comment on the ability of it to do arbitrary memory reads & what not, but that isn't suprising in thoery. It's much less scary than the article is making it out to be, although it is another attack surface to concerned with just like RDP or SSH.