I keep going back to the thought... it just makes too much sense to me. Iwata said it's not a hybrid, and I can't imagine he'd lie about it.... and nearly all of the big patents we've seen lately are playing a role in this latest rumor, except for the SCDs...
I'm still convinced, this isn't a hybrid, this is our portable. The TV docking seems like something that could have been added late in development (maybe not post Iwata, but maybe so)... and we still have the fact that NX is supposed to be a platform of devices, not a single device... Meaning what we're seeing here is "device 1".
Thinking like that (series of devices, this rumor focusing on a mobile version, and the fact that we're seeing developers starting to come out as excited for it), I think we're seeing the base of the NX, with the true 'console' SCD coming out around Christmas.
The dock is meant to be a stop-gap for the flagging Wii U sales for those that want a console experience (and one that should still outdo the Wii U even if it can't meet Xbone levels) until the SCD is ready down the line... With the base system containing a lot of the hardware (controller, storage, cartridge reader), the SCD can be a staggered 'upgrade' for a sub-console cost, with a bundle with both also being available in time for November Christmas shopping.
*spitballing*
All that said, I still don't imagine the SCD will/would compete with the Neo or Scorpio, it's just not Nintendo's style.
(edit) Keep in mind... a full on console with a full on handheld at launch would inflate the price pretty greatly, something Nintendo has experience with that ended poorly... I expect whatever the first NX device to be, it's going to be "affordable" compared to the other consoles (see the original Wii) with the SCD being about the same price as the base unit to extend it... For that reason, I don't think the dock will contain any additional hardware or be any more than what the rumor already says it is, just a way to get TV out.