The Tech Report published a review on the A first look at SATA Express with Asus Hyper Express storage device A quote from the article:

SATA Express combines Serial ATA and PCI Express on the same physical interface. Some next-gen Intel motherboards support the standard, and Asus has developed a RAID-infused Hyper Express storage device that's compatible with it. We take a closer look at SATA Express and the Hyper Express prototype to see what's what.

 A first look at SATA Express with Asus Hyper Express storage device @ The Tech Report