I understand that milksync currently syncs the "list name" into the "category" field in the WinMo database. Why not do tags as well (or have an option to do that "instead of lists" if you're worried about namespace collisions)?

I just spent hours tagging all my tasks with project tags, having decided NOT to use smart lists nor other lists for my projects. I sync'd my phone and ... no tags came over.

It seems to me that "tags<->categories" is a much more natural/intuitive fit than "lists<->categories"...