According to a recent article in the Seattle Times, the owners and the union are not only at odds over the Collective Bargaining Agreement (CBA) but that there seems to be in-fighting among the owners between the "haves" and "have nots".
The NFL is held up as the stongest and most thriving of the major 3-and-a-half sports, due largely to the CBA and the salary cap. Allowing this to go by the way side will be blindly wandering down the same dark alley that sent Hockey into a season long coma.
Hell, these blog sites and web boards are as active now as they are during the regular season, again, as a direct result of the salary cap. This genius invention not only keeps the sport in check, but provides year-round interest in the moves (and non-moves) that your team makes (or doesn't make) in the off-season.
Not renewing the CBA, and worse, going forward without a hard salary cap, could be the death knell for the NFL as we know it.