"in your case: especially the kernel"
err, im not dev, but i would say just the opposite, since the kernel is the part he has seen leaked code...
Okay, to make something clear, I didn't want to say we are interested in leaked or any other Microsoft-code, but I think if you have seen such code (some time ago) it's not a reason to be excluded from development in general. I have to make clear, that we (and me too) don't accept code from suspicious or unknown sources and we respect copyrights of course. If you follow the developing guidelines then we all will not run into problems related to the "intellectual-property-rights-mine-field".
Sorry for any missunderstanding
Matthias