SATA 6Gb/s is quite likely since the chipset features two SATA 6Gb/s ports but I doubt the SSD will be 6Gb/s. The SSDs in other 2011 Macs are 3Gb/s, even though the interface is SATA 6Gb/s.
Nope. They are mSATA SSDs (also known as blade SSDs). Basically, they use the physical connector of Mini PCIe but the signal is SATA. There are some other brands selling mSATA SSDs for MBAs, e.g. OWC. mSATA SSDs are certainly becoming more popular all the time though.