"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
iPhone 6 and iPhone 6 Plus Get Cracked in First Drop Test
The iPhone 6 did well when dropped on the side and back, but unsurprisingly suffered when dropped on its face. The 6 Plus, on the other hand, cracked when it landed on the side. However, it sustained little further damage when falling on its face.
Based on this one test, both phones may have performed worse than the iPhone 5 design which was described as "very durable" and survived similar drops in a previous drop tests. Without standardized testing, it's hard to draw definitive conclusions.