The NFL is considering adding a second game to be played in England.  The NFL currently has one game a year that is played in Wembley Stadium, which is in London.  From ESPN:

Commissioner Roger Goodell said Tuesday the second game could also be played in London or another location in the United Kingdom. The issue will be discussed at next week's league meetings and could be included in a larger plan to add up to two regular-season games to the NFL schedule.

The fan reaction we've had in London has been extraordinary. We would like to feed that passion," Goodell said after speaking at the Charlotte Touchdown Club. "We have a great fan base in the UK. There have been discussions of taking the second game and playing it in another market in the UK. That's something that we'll evaluate.

Of course the Commissioner is going to make it sound like a fantastic idea that has no negatives.  But there are negatives.  Do the English even care about American football?  Both NFL trips to England have sold out but I recall that a lot of Americans, expatriated or otherwise, made up the crowd.  I highly doubt the Tampa Bay Bucs will ever be as popular as any English Premier League team.

Teams can suffer from the logistics of traveling to England and American fans lose a home game from their teams schedule as well:

However, some players have been critical of the overseas game because of the extensive travel involved in the middle of the season. One team also loses a home game in the arrangement, a potential competitive disadvantage.

Saints coach Sean Payton was critical of the "sloppy" field conditions at Wembley Stadium last season and the logistics involved in playing a "home" game in London.

It doesn't take a genius to figure this is all about making more money.  The NFL sees this as a good opportunity to spread their brand to new markets and cash in even more.  The football purist in me just can't wrap my head around a NFL game being played in England, let alone a second.