Microsoft announces it is submitting 20,000 lines of source code

Some would say this has been a long time in coming, but others are probably
looking around to see if they can spot Babe the pig taking off:
Microsoft has announced it is submitting 20,000 lines of source code to
the Linux kernel under the GPL2 license.
Even Microsoft seems to be aware how strange this situation is,
describing the move as "a break from the ordinary". The code essentially provides device
drivers for Linux that help it detect when it is running on Microsoft's
proprietary Hyper-V virtualisation system so that performance is
improved.
Sam Ramji, the senior director of Platform Strategy in
Microsoft's Server and Tools division, said the code was there to
"enhance interoperability" between Windows and Linux, "to provide the
choices our customers are asking for."
Tom Hanrahan, the
direction of Microsoft's Open Source Technology Center (it has one of
them?) was more specific: "The Linux device drivers we are releasing
are designed so Linux can run in enlightened mode, giving it the same
optimized synthetic devices as a Windows virtual machine running on top
of Hyper-V. Without this driver code, Linux can run on top of Windows,
but without the same high performance levels."
Posting to the Linux Kernel mailing list, long-term kernel hacker Greg said "It's taken a long road to get here... there is still a lot of work to
do in getting this into "proper" mergable state, and moving it out of
the staging directory".
A few years ago, Microsoft was describing
the GPL as cancerous, so this seems like a major U-turn for the
software behemoth. Sure, the ultimate goal is there to make Linux play
ball better with Windows, but it's hardly like Microsoft was obliged to
make Linux run faster on Windows.
Is this, along with Microsoft's promise not to sue over Mono,
the first of many steps towards Microsoft joining the Free Software
community, or do you think it could end up being part of a Microsoft's
old embrace-extend-extinguish tactics?