This was the obvious next step for touch-based devices. Sapphire production seems to have gotten really affordable recently, and Gorilla Glass never truly delivered shatter protection, mostly scratch protection.
The Ubuntu Edge was going to be the (possibly?) first phone to offer a sapphire, so it's good to see others pick up the idea as well.
Ubuntu Edge was vaporware, and it was never going to be the first phone to anything.
The gulf between "oh yeah, it's going to have a sapphire screen and the best processor ever and photon torpedoes" and actually doing the necessary engineering before ramping up to hundreds of millions of dollars in production is enormous. Companies that ship real products aren't just now "picking up the ideas as well" -- any technology that you see getting significant investment has clearly already been in development for years.
Vertu has offered sapphire screens for a while now.
No reason to be skeptical. Sapphire is commonly used as a high-end alternative for bulletproof glass in armored vehicles. While it is a lot more expensive than bulletproof glass it is also much more resistant to weapons fire, which suggests its durability.
The Ubuntu Edge was going to be the (possibly?) first phone to offer a sapphire, so it's good to see others pick up the idea as well.