Hmmm. I'm usually pretty good at guessing the types of countries we'll see.
We just had three legs in South America, so we're not headed back there this season. If the Americas are done, it'll more likely be a single penultimate leg somewhere in Central America or the Caribbean. I'd hope for El Salvador, but I think Costa Rica is more likely.
Central/Western Europe really needs a break - Austria and Germany have both had a full leg and a train transfer in the past three seasons, and in the past five we've also had the three central Scandinavian countries, the Netherlands, Belgium, Lichtenstein, Switzerland, Italy, France, and the UK. PIIGS is still unlikely, but it's possible they'll throw someone a bone and help out a struggling country's tourism industry. I'd still think we're more likely to get eastern Europe or the Balkans though. If we get PIIGS, it'll be two legs in Spain and Portugal. If we get eastern Europe, I'd go with Hungary again, or Slovenia and Slovakia. If we get the Balkans, it'll be Serbia. Outside chances for Bulgaria, Turkey, and Malta.
Africa? Tanzania's the first country to get a third official visit, and only Morocco and South Africa even have two. South Africa's probably the more likely of the two to get a repeat visit, but if we get another new country I'd be looking at Cameroon or Angola. We do need to hit that whole central African region eventually.
The Middle East is pretty much out of consideration thanks to the Arab Spring. Possibly Jordan, but I doubt it.
We did India last season, we've done Bangladesh fairly recently, Pakistan's not happening any time soon, and Nepal's still unsafe. Sri Lanka is the closest we'll get to a central Asian country.
In southeastern Asia, we just went to Indonesia and Thailand two seasons ago, and Cambodia, Vietnam, Malaysia, and Singapore have also been done not that long ago. Of the six Vietnam is most likely, although I'd prefer Malaysia. The only new countries in the region would be Brunei (which doesn't allow foreign TV crews), Burma (which would be a nightmare from a security perspective), and Laos.
Eastern Asia is where it gets a bit harder. As the producers seem to love the idea of showcasing the stereotypical "Oriental" countries, we've done at least one of Japan, China (including Hong Kong), and Taiwan in eleven of the past twelve seasons. Japan was last season and Taiwan was the season before, which means it's China's turn again if we want to make it twelve out of thirteen. Plus, Taiwan's too small to justify two visits in three seasons, and they wouldn't have done the Hiroshima trip if they'd been planning to return to Japan this season. If we don't, the southern part of South Korea is a distinct possibility.
Oceania, Oceania, Oceania. I'm still holding out for the southern part of Australia (Melbourne!), but given the show's "Leg 1: Big city. Leg 2: OUTBACK ADVENTURE." usage of Australia in all four previous visits, it's not likely. If Australia turns up, I'd go with Adelaide and Alice Springs. It's certainly time for New Zealand again though, and preferably without Auckland for once. The Pacific islands are likely to be ignored again, but since there didn't seem to be a reason for the charter flights to Ngorongoro Crater last season (as they were able to drive to Mto Wa Mbu, which we know from TAR5 is within driving distance of the Kilimanjaro Airport), it's a very remote chance they might have done it to prepare us for more charter flights in future.
With the finish line, we've done the southeastern US twice recently and California twice before that, so it should be somewhere in the north or centre of the country. I'd hope for New Orleans, but I'd bet on somewhere in the Midwest.
In summary, I'd predict:
1: Los Angeles to Portugal
2: Portugal to Spain
3: Spain to Hungary
5: Hungary to Cameroon
7: Cameroon to South Africa
8: South Africa to New Zealand
9: New Zealand to Tonga
10: Tonga to South Korea
11: South Korea to Costa Rica
12: Costa Rica to Minneapolis