superfast ssd (PCIe connector) to MBP mid2012? is it possible to put one of these new generation ssd to my MBP with pci express connector?

PCIe SSD
I don't believe it is possible as the Macbook Pro 2012 doesn't come with a PCIe according to the Apple specifications. 

http://support.apple.com/kb/sp649

You can put a standard aftermarket SATA SSD in though.