I really believe the NFLPA is lining up on the wrong side of this upcoming dispute. Here are more comments from Smith about the uncapped spending, mainly focusing on the low end of the spectrum:
NFL News Feed: DeMaurice Smith says union will monitor NFL teams' spending in free agency with 'a very keen eye' - Mark Maske
Seems like they will argue collusion based on not spending as much, but I think the league could easily demonstrate via baseball, that low end teams salaries were artificially propped up by the salary floor, and that without it, low end teams are likely not to pay as much regardless of revenue sharing.