IMO, Dak right now isn't nearly the QB Romo is but thats ok. However, the great part of Dak's play is Dallas no longer has to worry about QB of the future. Dak has done more than enough to warrant Dallas to make him the post Romo starter. How that goes is up to Dak and if he can make the necessary progression from rookie to veteran.
Whenever Romo comes back, it will be his last stand. I think coaches, ownership, and players know it. What this all means, Cowboys no longer have to "worry" about Romo getting hurt. Whenever, Romo says he's ready to play, you put in him. If/When he gets hurt again then it's back to Dak and then you move on in the off season. If Romo comes back and continues his high level play, then you're back to being a truly dangerous team that IMO would be the front runners to win the NFC East and Dak can learn from his starting stint on what to work on going into the off season. Its a win/win situation no matter what.