I guess with the plan not to have the Final 3 teams on TES, we can only make the following accurate assumption: Nathan & Jennifer will make the Final 3. They are one of the strongest teams, and they are the annoying/villain team. This team tends to get to the Final 3, so why should this team be any different? I just hope they don't win!
Right now, I think T.K. & Rachel will fail to make the finals, but it could be Nicholas & Don.
While I think you are correct about who the race comes down to. I strongly disagree with calling Jennifer and Nathan the annoying/villain team (well the villain part anyway).
While you can certainly call them the typical bickering couple team (and of course that can be annoying). What evidence have we seen in episodes or clips that would earn them the title "Villain".
Usually that goes to one or two types of teams.
1. The type of team that tries to use manipulation to get ahead of other teams.
2. The team with the worst overall behavior.
And in this season (at least to date) that doesn't apply to this team.
We haven't seen them trying to trick teams (even told other teams about Azaria & Hendekea doing that with flights), no telling people not to help others, no stealing cabs, no pushing other teams out of the way, to bribing drivers, ect. The closest we have seen is Nate talking about his "dream" of being in a race for the finnish line and throwing his pack to trip a team. Really we haven't seen much of this behavior in this season now the teams talk about who they find to be underhanded and thats so far been Azaria & Hendekea (by some teams, and we have heard them talk about in clips giving false info to others), Ronald & Christina (who have admitted giving false info), and probably the most negative talk as been about Kynt & Vyxsin (about trying to give false info out). Now in all those cases, thats exceptionally mild for what is normal "Villain" moments.
As to the overall poorest behaving team. While they certainly bicker (and some times out and out fight), they tend to keep that internally within their own team. We haven't seen them arguing or fighting with other teams. And we haven't seen them fighting with locals. The closest we get to that is hearing about them getting in a financial disagreement with a local over the bill for a phone (we don't see or hear about it, and we don't here them talk about inappropriate behavior so we can't judge that. And then being upset about he cab driver who wouldn't pick them up. And that was I can't freakin believe this, that is so unfair, type of comments.
With Ronald and Christina (well Ronald), we see a team that hits all aspects of poor behavior. We get internal team fighting (in as many episodes as Nate & Jenn and in just as hurtful manner), we have a team that fights and argues and cusses at other teams (all apparently one sided), we haven't seen a team fight or cuss back (the closest is Kynt insisting that he wait until they are finished with their transaction). And we have a team that also gets mad and vocal to locals (we see and hear about this in clips. And we hear about it being done inappropriately (So I think we can judge). We have the only team (that I can recall in the history of the show) who fought we task judges. We have a team that has made comments about that were negative about a countries people (Again clips were we see Ron talk about the French).
We have seen a total of one episode where they didn't fight (episode one) and that might be because they didn't or it might be because with 11 teams, they didn't get much air time, who knows. Even this last episode where Christina says they didn't fight they entire leg, wasn't accurate, as the airport scenes showed. Though for them, this was indeed a better episode.