New England Patriots owner Robert Kraft is over in England right now, doing some promotional work for this season's Patriots-Rams International Series matchup. During his trip he conducted an interview with Sky Sports in which he stated that he planned on pushing to get a full-time NFL team in London before this decade is finished. This issue is of some note to 49ers fans in part because 49ers owner John York has long been head of the league's international committee. York's voice would not be the final say on the issue, but he would be prominently involved in the discussion.
Kraft made good points about global expansion being the best way to grow the game, but having a full-time franchise in London would be an interesting challenge. The flight time to London is not ridiculous from the east coast, but for anybody off the eastern seaboard, it would be a more sizable trip. One option for travel would be working around bye weeks. If the NFL expanded to London, it could be possible the league alters the schedule to develop more bye weeks across the board. The league could conceivably get a little creative with their schedule to make this happen.
The NFL has had success in London for these games, generally drawing strong crowds. There are plenty of American fans in England, but just as important, if not more so, is that you have a lot of British fans of the game. As I recall from a discussion with LondonNiner when I was over for the 49ers-Broncos game, the NFL gained a sizable chunk of fans in the '80s when the English Premier League had some labor issues (he can clarify that). The question of course is whether they would be able to support a team over a 16-game season, year in and year out. I am inclined to think that could happen, but it is still a big question to answer if the NFL is going to find success with a London-based franchise.