There's nothing but anthropocentrism to imply we're it. Another technological species may emerge at any time, especially if we nuke ourselves or are overtaken by antibiotic-immune pandemic/s. It would likely happen gradually as a species diverges from one of the social apex predators. There would probably be several overlapping species competing and interbreeding.
> [...] or are overtaken by antibiotic-immune pandemic/s [...]
Unlikely. Even without any antibiotics, pandemics might kill in the order of 50% of the population (see black death in Europe for example), but as long as a few thousand immune people survive they can rebuild.
That makes a big assumption that all pandemics are not 100%. A total extinction event could be something else: long-lived radiation beam or large impact. Furthermore, some event need not kill all humans but only enough to allow another species room to master its environment and begin to develop technologies.
