If it includes Nvidia gamestream in any form, that'll tip me over the edge. I've bought a Shield Portable and Shield TV, I got rid of the portable. Two reasons why: small screen and fold-out design, other than that it was a great device. Switch has neither of these problems so it could be the best mobile console Nintendo has ever released, not to mention more powerful than the WiiU on the docked side. Being able to play my PC games with Switch in any room of my house or out on the deck would be the cherry on top.
It's not an unreasonable assumption that it might have gamestream, either, since Skyrim was shown in the trailer but isn't confirmed to natively support Switch (yet).