I'll begin my analysis with likely ideas:
South America: Typically, S. America is visited every other cycle, but TAR 22 broke the cycle because it headed to Oceania first. Since I expect TAR 23 to head eastward, it logically makes sense for TAR to head south first before heading to Europe/Africa. Three legs minimum because of the gap since TAR 20, with one country being a double leg. Peru is a good candidate for a first destination/double leg, and because Argentina was featured during the last visit to S. America, it's probably Brazil or Chile's turn.
Europe: Western Europe has been extensively featured in the past few cycles, so I'm hoping for (and expecting) Eastern Europe, namely the area around the Balkans. Hungary and Bulgaria are definite possibilities as well. Due to the numerous European legs last year, I'm only expecting two legs; I think Africa will be visited before Europe though.
Africa: In accordance with TAR's recent patterns, I'm expecting Africa to be visited in TAR 23 and skipped in TAR 24. There will be two legs in one country as usual; I actually think that Johannesburg, South Africa would be a fairly good choice to be revisited, given the relative ease of the hop from Brazil. I don't know where the second leg in S. Africa would be. Dark horse candidates include Ethiopia and Rwanda; if so, Europe comes first and the overall route becomes quite similar to TAR 20.
Asia: This is by far the murkiest area to predict because there's a lot of available areas to explore. Here are just some of the possibilities for the three or four Asian legs: India (maybe unlikely due to the rapes, but definitely two legs if visited), Sri Lanka, Malaysia, Laos, Philippines, Nepal, and China.
Oceania: No visit because New Zealand and French Polynesia were just visited.
North America: Likely no visit to Central America or the Caribbean, unfortunately, unless Africa or South America is removed (which I don't want to see happen). We're looking at a final city in the Midwest or the West Coast. Thus, I lean towards Seattle or Chicago.