Did Microsoft's 20k lines of code make it into Linux?

First of all, yes Microsoft has code in the Linux kernel. They are "in the works of being put in" in the sense that they are in the staging area and thus do not appear when configuring the kernel unless staging drivers are enabled. However, they are in the main kernel tree and will be present in any downloaded tarball or git clone. You can view them here:

http://git.kernel.org/?p=linux/kernel/git/torvalds...

Secondly, the code is used mainly to create / improve support for running the Linux kernel in Microsoft's Hyper-V hypervisor on top of Windows.

http://en.wikipedia.org/wiki/Hyper-V

Put it to you this way: Linus Torvalds very openly uses Windows on some of his computers personally and STILL said in a public email about their hibernation algorithm, "Just because Windows does it what makes you think it is EVER a good idea?"

I haven't heard so it may not have been rejected but its probably not in there because 1. they have a bad reputation among techies for sloppy coding and 2. they have a contempt for other peoples algorithms and code which makes peoples opinion of their code lower. I use the Linux kernel and if it is good code properly contributed I have no problem with it being included, but I am also confident of the review process and if it fails to be either then I am confident it will not run any of my computers.

the Samba and Wine projects are about the only place microslop is required for use in Linux