2015: The year of PCI-Express SSDs? @ Hardware.Info
 

For laptops, M.2 will without a doubt become the standard. For servers, it'll be a combination between PCI-Express expansion cards and SFF-8639 2.5″ drives. Based on the many talks we've had with motherboard and SSD manufacturers over the course of last year, we expect that PCI-Express expansion cards will have the best chance to succeed in the high-end desktop market. For budget desktops, Serial ATA will remain the most important interface for quite some time. However, because we expect that SSD manufacturers will release many individual M.2 SSDs for the laptop upgrade market, one might also assume that this form factor could also succeed in the desktop market. Like we mentioned before, we're a little sceptical about SATA Express, because the standard is already outdated before the first product has even hit the market.

http://uk.hardware.info/reviews/5772...i-express-ssds