Don't think I would get a MGSV port. I really did like MGSV on PS4, but I can't see playing it portable. I did buy Disgaea for Switch and that worked well. Game is excellent portable.
What will be interesting is if there are any major cross platform releases I want. Depending on the game it will be a tough decision against better graphics for PS4 version or the versatility of the Switch. It will definitely be a decision made on a game by game basis.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut