I think widespread corruption at fifa makes this situation a little bit different. I doubt countries will boycott it after Blatter's resignation but there will surely be a few countries like England complaining that they should have the world cup or it should be put back to another vote. They wont pull out though.
As I had posted earlier, a lot will depend on the FIFA presidential vote. If some US-puppet, such as Prince Ali is elected as the president, then he can legitimately cancel the event in Russia and conduct another vote to decide the hosts for 2018. If someone else is elected, then indications are that England might try to organize a paralell event in London.
The UK did want to take the place of Qatar as the host of the 2022 World Cup they even said they have the facilities for it, that said I do find it concerning that the United States wants to control international football/soccer and while FIFA is one corrupt organization it does remain one of only a handful of professional sport organizations not directly in the control of the USA.
Which is why Sepp Blatter despite the corruption was still able to acquire the amount of votes he did, and even teetering on the brink of disgrace, Blatter was still able to command almost two-thirds of the membership While patronage and funding such as the case with Ireland goes into soccer in my opinion the US just wants some of that gravy train and take it under their wing that said it looks like the corruption is starting to unravel after all these years.
On one hand FIFA has brought soccer tournaments to many places around the world such as South Africa, Brazil, Russia, and soon Qatar and truly has a global footprint instead of a US centric one that only hosts tournaments with countries it has good relationships with so my feelings are mixed about what this means in the long run.
MLB,NHL,NFL,NBA, and Boxing to an extent are major professional sports leagues with most games played in the United States and players are attracted and move there in order to compete, Soccer/Football meanwhile tends to remain a more internationalized sport with Premier Leagues in the UK, MLS in North America and the African League and all of them meeting under the FIFA banner to compete, if this leads towards a strong regionalization of FIFA it concerns me that international soccer will slowly over time become a compartamentalized representation of countries and not what it is today which admittably is also partially due to Sepp Bladder.
http://www.theguardian.com/football/2015/jun/04/england-ready-host-2022-fifa-world-cup-qatar-ditched-culture-secretary-saysAs the Guardian humbly said Under Sepp Blatter, it wasn’t all bad
http://www.theguardian.com/commentisfree/2015/jun/05/sepp-blatter-fifa-world-cup-south-africa