popatim :
Most likely the manufacturer gave you mSata so you could actually buy something and stick it in their. M.2 drives currently can be had in either of the two 2-lane configurations but no one has a 4 lane available on the market and the 2-lane ones are hard enough to find to begin with. I'm not even sure all 4 lanes can be used at the same time but I also dont see why it couldnt. I'm sure in 10 years we will have some other new bus that replaces this anyways.
Quoting from the first article I posted, there's only one mobo like that for now:
"On Z97, the PCH-provided M.2 and SATA Express ports are mutually exclusive. You cannot use both simultaneously. Asus is adding third-party SATA Express controllers to some boards, so obviously those are able to operate independently.
And then there's ASRock's solution: borrowing four lanes from the CPU's PCI Express controller to create the Ultra M.2 slot."
As for what manufacturers are making, there's a lot of M.2 sticks with SATA 3 interfaces. Only few real PCIE M.2 SSDs like Samsung's elusive XP941 (used in the article above for some interesting reasons) and Plextor's M6E.
But yeah, all things considered, this SSD technology is still in diapers.