"If you make modifications to the Sample Code and make those modifications public in source code, text, or any other descriptive (non-binary) format, you give to Microsoft, without charge, the right to use, share, and commercialize those modifications in any way and for any purpose."

basically, anything you make with the SDK, microsoft can commercialize and sell

edit: changed steal to commercialize

Basically, it isn't stealing.

It's not stealing if it's in the agreement.

If you agree/sign the agreement, then it's not stealing. You're GIVING Microsoft the ability to do this.

basically, anything you make with the SDK, microsoft can commercialize and sell

@imsh_pl: thanks, gonna change that at the top

It says it's only if you release the code publicly, not the binary.

Makes sense. They don't want someone to make something cool and then lock Microsoft out from every using that thing. I see it as more a feature protector, their not gonna steal the game you make and sell it. But they also don't want to have you saying they can't use some technique because you came up with it first. 

It would be nice if you got something for making it...