I cannot see FIFA moving the WC no matter what. It would turn into a huge legal battle as Qatar will show the investment they have made in order to host it, namely the stadia, roads, metro system, hotels, etc.
The only cause for moving it will be if there is a war that breaks out in the time leading up to it.
With the current situation anyone who is planning on travelling over for it, either needs to stay in Qatar, Oman or Kuwait (dry) as you cannot fly directly between UAE and Qatar.
For what it's worth the stadiums were built in modules (i think all were but could be wrong), so after the word cup they will be broken back down and shipped to Africa and rebuilt there.