This is a very complicated issue. Let me take a pass at it.
Labor Law, Unions, and Collective Bargaining Agreements
The NFL currently operates as a virtual monopoly on professional football in the U.S. It would normally be subject to extremely stringent U.S. antitrust laws, but is exempt because it is protected by a labor contract agreed to by the NFL Player's Association. The government essentially allows the NFL to run a monopoly so long as it benefits the players as well as the owners. As such, this agreement is subject to federal labor law regulations. These regulations came out of late 19th/early 20th century industrial disputes between corporations and workers and are embodied in U.S. labor law, particularly the National Labor Relations Act of 1935. Because the U.S. government does not want to micromanage private industries, as long as their is a valid agreement between the employer (the NFL and the franchises) and the workers (the players and the NFLPA) all is well. However, given the history of U.S. labor law, the fact that the NFL has a virtual monopoly on professional football, and the visibility of the sport, this is a touchy subject and one that will get intense government scrutiny if things get acrimonius.
The NFL and the CBA
The NFL has traditionally been dominated by strong owners and weak player repesentation. Prior to 1956 there was no NFL Player's Association (NFLPA) representing the players, and it wasn't until 1968 that the NFLPA won recognition from the owner's and the first Collective Bargaining Agreement (CBA) was put into place. A CBA is the standard tool under labor law spelling out the agreements between an employer or group of employers in an industry and one or more worker's unions, regulating things such as pay, benefits, hours, representation, right to strike, etc.
In 1982 the NFLPA striked for 57 days over the percentage of gross revenues that would be allocated to the players. That strike resulted in the 1982 season being reduced to 9 games. Another strike in 1987 led to the brief use of replacement players by the NFL, the dissolution of the NFLPA as a union and of the CBA, and an antitrust suit filed against the NFL. That litigation was eventually settled in 1993 with an agreement that permitted free agency, and the NFLPA was re-constituted as a union. The 1993 agreement has been extended 5 times, most recently in 1996 when it was extended through 2011.
The Owner's Decision to Opt Out
In May 2008 the NFL owner's opted 32-0 not to renew the current CBA, believing that it was not working adequately. At the crux of this decision was the belief that the agreement under the old CBA to allocate 60% of all NFL gross revenues to player salaries was not economically equitable.
Unless a new CBA is put into place, after the 2010 season ends (February 2011) there will essentially be no labor agreement between the NFL and the NFLPA. That could result in a strike, cancellation of the season, antitrust suits, and other such measures.
What This Means for 2010 and the Draft
The current CBA covers rules for salaries, free agency and the draft, including things such as the salary cap, how one qualifies as a free agent, the franchise and transition tags, and the NFL draft. The CBA also included provisions for a transitional period if it should not be extended, which change some of those rules in anticipation of a period of uncertainty before a new CBA is put into place.
If no new CBA is agreed upon before the current season expires in February, then free agency will be governed by those transitional rules, and there will be no actual salary cap. If a new CBA is agreed upon, it will presumably have explicit rules addressing free agency, and probably some kind of cap or similar structure.
What this means is that the rules we are used to won't necessarily hold. Specifically, it may take longer to qualify for free agency, and for restricted vs. unrestricted free agency. For example, under the old rules Logan Mankins would be a UFA in Febuary 2010 when his 5 year contract expires; under the transition rules he would only be an RFA, because 6 years rather than 5 would be required to qualify for UFA status.
This means that the number of truly available FAs may be significantly reduced if no new CBA is put into place by February 2010. The transitional rules also have some limitations on signing external FAs, particularly rules that prohibit the top 8 playoff teams from signing external FAs other than to "replace" FAs that they lose. This would prohibit the Pats, for example, from simply going out and signing someone like Julius Peppers if he became a FA, unless the Pats lost a similar caliber player (such as Vince Wilfork). I don't understand much about these rules, but as I understand it their purpose was to promote stability in the transition period until a new CBA was reached, and prevent certain teams from simply spending uncontrollably and being able to do the kind of things that the New York Yankees have done in baseball.
The other major implication is the prediction that a new CBA will include a rookie salary scale (such as that used by the NBA), so that unproven rookies drafted at the top of the draft won't be making more than established veterans, and so that teams drafting at the top of the draft won't be essentially penalized by the huge salaries they have to pay to unproven players. Because of this likelihood, it is anticipated that a huge number of eligible juniors may declare for the draft in 2010, rather than wait for 2011 when they may get lesser salaries under a salary scale.
The general feeling for a long time has been that we won't have a CBA in place by the time the 2009 season ends, and that we will be operating under transitional rules. A lot of teams (including the Pats) have been operating under this assumption. This affects things such as the need to re-sign players who may be eligible for free agency, and a lot of other areas.
Hope that covers it. That's a brief overview, and it's much more complicated than that.
