@James:
(1) From Raymond's description, the list was a member of another structure so that wouldn't have worked anyway
(2) There's no requirement I can find at the page you linked or a couple I followed from there. All it says is that the SLIST_HEADER must be aligned at MEMORY_ALLOCATION_ALIGNMENT. _aligned_mallloc() is one way to achieve that (which is why they refer you to it) but it's by no means the only.