At the end of The Doctor's Wife, the TARDIS points out that she will never be able to personally speak to The Doctor as a stand-alone, sentient being. However, we have already seen that the TARDIS is capable of interacting in the form of an image of a person, in a form of voice-activated interface.
We've seen The TARDIS play back holograms of The Doctor on a few occasions (Blink, Parting of Ways, etc.) However, those were pre-recorded events, which mostly show the TARDIS's capacity to display full-sized holograms.
However, when The Doctor was dying in Let's Kill Hitler, the TARDIS produced a series of holographic images of current and former companions, which interacted with The Doctor via normal speech communication. These were not sentient holograms driven by the TARDIS's consciousness, but rather intelligent user interfaces.
What we see appearing to Clara appears to be another case of this interactive user interface, and not a fully self-aware TARDIS consciousness.