Zutara 70%
Kataang 30%
Kataang is because of its obviousness. However, I seriously think Zutara has more chance. Either way, those two becoming friends will be awesome (the fighting together was fantastic!), and if it stops there, I'll survive.
For all those people saying 'oh, but they've "never" shown zutara teasers before', umm, why would they only show pro-zutara shipping stuff? Why not have some pro-kataang stuff too to make it more suspenceful and whatnot? (like you guys keep saying is the only reason they do this stuff). Personally, I would be much more excited if they had a pro-kataang moment as well as the pro-zutara (or at least pro-zutara friendship for you kataangers) - it would make it so much better, and much more "omg, which ship will happen?". But because it was all pro-zutara, and the finale is coming up....seriously, you guys can't keep saying they are just spinning us along. CoD was ONE moment (omg, will she heal his scar). This trailer has at least 5 pro-zutara moments, and 1 anti-kataang moment. Odds aren't in your favour guys.
But still, Kataang could happen, but I think zutara is much more likely at this stage (and no, it wasn't just the trailer that made me think that. I've thought it for awhile, and the trailer just re-inforced my opinion).
And i agree with cancerthecrab. Half the time I say things like the above, its just to see the kataangers reactions