Just a few thoughts.
The last Los Angeles to Europe start was in 14, and Amazing Race hasn't gone to Europe first since 17. Either Europe won't be the first continent or Los Angeles won't be the start city.
Amazing Race has alternated Australia and New Zealand every 4-5 seasons for a while, an Australia visit won't be likely for this season.
Brazil is hosting the World Cup in 2014. I do think Brazil will be visited in one of the next two seasons, it doesn't hurt that it hasn't been visited since 18.
Africa has been present in 3 of the last 4 seasons, I think this season will skip it.
My prediction is 3-4 continents in total. USA, Central or South America, Europe, Asia, USA.