NBA teams using internal data are projecting the salary cap to jump to between $88 million and $92 million per team, sources told ESPN. To compare, this season the cap is set at $63 million and next season it is projected to land at about $66 million. To put it into perspective, the largest salary-cap jump in history is $7 million in one season. What happens in 2016 could triple that leap.
http://espn.go.com/nba/story/_/id/12461874/players-union-rejects-salary-cap-smoothing-historic-cap-increase-nba-set
This is going to massively change the league. The current system is not designed for this much money to be available to sign players to extensions.
First off, I highly doubt any player signs a contract this summer even at their max (like a guy like Jimmy Butler).
I think in 2017 (assuming there is a "lockout" while they negotiate) we could see maximum salaries eliminated and the teams will switch to a NFL style cap (hard team cap, no max for player salaries, most teams pay roughly the same amount) but owners will get non-guaranteed contracts for this massive change and the fact player salaries might uptick to say 54%.
The Bulls decision to not give Jimmy Butler 4/54 (or whatever it was close to that) is going to look like one of the dumbest decisions of all time considering they had to know this could be the salary outcome.