] The company is expected to release on Thursday a new
] version of Services for Unix (SFU), a collection of tools
] that help Windows systems to work with installations
] based on the Unix operating system and its open-source
] derivative, Linux.
]
] Microsoft previously charged $99 per client or server to
] use SFU. But the new version, 3.5, will be free for any
] customer using a current Windows operating system.

I wouldn't say they are "taking on linux." They are just offering something that lets me mount an NFS partition on a windows box. This is needed mostly because NBT is overly complex and the Samba configuration files reflect this. Samba has two modes of configuration:

1. Really complex
2. Web based

NFS is neither complex nor web based. Thats why people prefer it. It would be easy to create a simplified interface to samba that has similar syntax to /etc/exports, but no... and hence this is needed.

Microsoft takes on Linux with free tools | CNET News.com