More PlayStation ports of great games sounds good to me.
The former title should look especially nice running at 1080p and 60 frames per second. As for Nidhogg, its online multiplayer is cross-system (PS4 vs. Vita) and two people can compete against each other using a single Vita, too. Just don't get overly worked up and drop the system.
Dust: An Elysian Tail Coming to PS4 [PlayStation Blog]
Nidhogg Coming to PS Vita: Cross-Buy, Online Play, and More [PlayStation Blog]