I wish I shared your optimism. There won't be any FA additions that will be exciting. There's no cap space. So check that off your list. The draft is a crapshoot, and the Boys's history of drafts is mediocre at best.
There are too many teams in the NFC that are much more talented and/or younger than Dallas.
Let's say Dallas gets a FA or two that become starters, and have a draft where they get solid contributions from 3-4 players; does that make them better than SF? Seattle? ATL? Or even Wash?
Their current talent base is old, unproven or has health-concerns. Romo, Witten, Ware, Ratliff, and Austin are all on the downside of their careers. Murray misses almost as many games as he plays. Lee misses too many games. Carter has a checkered injury history.
So the young, talented (pro-bowl caliber) and healthy players consist of Tyrone Smith, Dez Bryant and Brandon Carr (Claiborne doesn't belong in that category yet, but there's hope). A LT, a WR and a CB. Good building blocks, but where' the DL? Teams that win have outstanding OL and DL, and Jerry Jones consistently ignores this or gives it lower priority than he does acquiring flashy perimeter players. Jones isn't alone in this regard, but he's not good at drafting or thinking about long-term ways to build a consistent winner like Pitt, NE, ATL.
There's no way this team contends for anything meaningful next year short of a miracle "get hot and lucky in the playoffs" type season. And I don't see them beating out Wash or NYG in the East to even make the playoffs in the first place. And certainly won't be as good as GB, NO, or the NFC West Runner Up in order to make a Wild Card.
8-8 is about as good as it can get next year.