Let us say I can pinpoint the exact endpoint of a teleportation, e.g. with Trace Teleport. Is there any way to find out what is coming? In 3.5 there is the spell Anticipate Teleportation that at least gives the creature's size and how many creatures are coming, but I cannot find an equivalent in Pathfinder. Is there any way to know?
Trace Teleport covers that already:
Whenever you detect the origin point or termination point of any teleportation effect with this spell, you can study that origin point or termination point for 1 round. If you do, you can attempt a caster level check (DC = 11 + the teleportation effect's caster level), taking a –5 penalty if the effect occurred more than 1 minute ago. If you succeed, you gain a glimpse of the teleportation effect's termination point (if you detected an origin point) or origin point (if you detected a termination point).
This means that you can see the origin point of this teleportation effect.
You do need a round for that, so most teleportation spells will be finished before you have time for that, since they are instantaneous, but that also means that you will immediately see what is coming out of the teleport.
The spell anticipate teleportation only worked on willing creatures, so it wasn't really great to know what and how many enemies are coming out of a teleportation effect, and it could anticipate because you had the option to delay the effect for a round.
As for instantaneous teleportation, your only option would be to use a Divination (or similar) spell and anticipate that someone is going to teleport to your location.
Or to ask your GM to convert the greater anticipate teleportation spell from D&D 3.5e to Pathfinder.