I would self-immolate for a game that simultaneously served as the sequel to both HL2 and Portal 2 (i.e. Gordon Freeman has both a gravity gun and a portal gun)
Wow, they totally fell under my radar, which is impressive when they own the #1 game distribution platform in the world. I remember seeing mention of Artifact, but didn't notice DOTA at all.
Valve have stated over and over that teleport locomotion is what they believe is the correct one. Portal's mechanic is about movement as much as portals - it simply wouldn't work in this environment.
The Portal/Half-Life universe (they're the same) itself? Absolutely.