I don't think the Price will be close to 300$ and it must be around 400-500$ considering Shield of Nvidia costed 300$. We already have portable PC like MS Surface Pro and future Ultrabooks which is good enough for everything than this Steamboy.
GAMING is not about spending hours to pass/waste our time just for fun,
its a Feeling/Experience about a VIRTUAL WORLD we can never be in real, and realizing some of our dreams (also creating new ones).
So, Feel Emotions, Experience Adventure/Action, Challenge Game, Solve puzzles and Have fun.
PlayStation is about all-round "New experiences" using new IP's to provide great diversity for everyone.
Xbox is always about Online and Shooting.
Nintendo is always about Fun games and milking IP's.