Big news on the Facetime front is that the new cameras on the front and back of the iPhone 6 are way better! From Apple’s Camera page for the iPhone 6:
With a larger aperture and all-new sensor technology, the front-facing FaceTime HD camera now captures 81 percent more light. It also has improved face detection. And its new burst mode takes 10 photos per second. So whether you’re trying to snap the perfect selfie or connecting with someone across the country, every image looks just right.
The f2.2 aperture means the camera lets more light in (giving you better low-light images). The lower that number, the better (and generally only high-end cameras can get down to f1.8.
Also worth noting: there is an improved HDR (High Dynamic Range) videos with the front-facing camera for more contrast and vivid images.
All-in-all, this is huge camera upgrade that will make your Facetimes even better.