Ars has an article on this. http://arstechnica.com/information-technology/2016/03/ubuntus-bash-and-linux-command-line-coming-to-windows-10/
Our understanding is that these are not recompiled or ported versions of the programs (as are used in tools aiming to provide a Unix-like environment on Windows such as Cygwin) but instead unmodified programs. Microsoft is describing this in terms of providing a Linux-like command-line environment at the moment, but from what we can gather, there's little fundamental restriction to this, potentially opening the door to running a wide range of Linux programs natively on Windows.
