A lot of smart people think Roger Goodell and the NFL are dead-set on moving the Jacksonville Jaguars — and, failing that, some other, any other team — to London. Keen-eyed readers will have already noted that London is not on the same continent as the rest of the NFL's existing teams. And West Coast squads like the San Francisco 49ers already bemoan their long trips. How do you think they'll like 10+ hour flight to London? Of course, the league can accomodate visiting teams with comforting byes after their trips, as it already does for the teams that play in the NFL's annual Wembley Stadium contest. Playing abroad also gives them a nice marketing opportunity. The bigger problem, though, will be for this London team. They're going to get their asses kicked.
The London Jaguars — let's assume for a moment that this will be their name, though it makes them sound awfully like the New York Red Bulls, i.e. some symphonic marriage of product and opportunity — would play eight games in London and eight games in the continental United States. During the 2012 NFL season, the longest road trip was Seattle flying to Miami to face the Dolphins, a distance of ~2,700 miles; every single London away game would be a longer trip than that. If the league tries to mitigate this by creating lengthy away stints for the Jaguars, they'll be stranding players far away from their native practice facilities and, presumably, families and homes.
What would likely make the most sense logistically is these long road trips, though, making their schedule an absolutely excruciating gauntlet of away games. And even at home, their opponents will constantly be getting up emotionally for a "special" game. The crowning injury might be night games. Historically, teams from the East Coast lose to teams from the West Coast in night contests, because 8:30 pm isn't a natural time to be performing strenuous athletic activity in the first place, and when you factor in the time difference, by the time the game is over the East Coast teams can feel like they're playing at 2:30 in the morning.
Considering London's geographic location, they'll be the ultimate East Coast team. London is five hours behind New York City, meaning that an 8:30 pm EST start would feel like 1:30 am London time to them. Considering the havoc this would wreak on a player's mental and physical performance, it may not even be realistic for the London Jags to play in primetime, and since primetime is regarded as the NFL's premier platform for spotlighting teams and games, that would marginalize its value as a franchise.
At this point, all indications are that Goodell's pretty set on the NFL in London. But — and this doesn't even include issues like luring free agents and coaches out to London — what might be good for league might not be good for the guinea-pig franchise. At least if it cares about winning. Which the Jaguars haven't, traditionally. So I guess they're all set.