There's no Vegas line yet, but the smart money says the odds aren't good. There have been seven previous attempts to create a league to take on the NFL. Six of them failed -- remember the WFL? the USFL? The one that succeeded, the American Football League, did so by merging with the NFL.
Still, there are powerful incentives for NBC and TNT (owned by Time Warner, the parent of this web site) to make this league work. Even with diminished ratings, football offers one of the last true mass audiences that advertisers crave. And at least the pair will be losing money with their own pigskin.