It won't be glass. It will be liquidmetal, which is a bulk metallic glass. Going glass only would be nothing new. Hell the S7 series is made of glass. Liquidmetal, I imagine, will look and feel different than glass.
This leaves me with several questions.
Will this redesign mean no more home button? (I hope so.) Touch ID will be featured in the screen itself.
What will the iPhone 7 feature? Thinner? Same thickness but more battery life? Essentially the iPhone 7, assuming this report comes true, will be a stop gap model to bridge between the 6S series and the new redesign in 2017. Seeing how important the iPhone is to Apple's revenue you must imagine they need to offer something special come fall regardless if the huge changes come in late 2017.