When Snap to Grid is enabled, artboards now respect it, both when moved or get created... unless you hold Shift to constrain proportions when resizing or making it a square.

Totally works for rectangles, I can see no reason to prevent artboards from behaving in a similar fashion.

Here’s a somewhat similar request about these also misbehaving with smart guides:
http://illustrator.uservoice.com/forums/601447/suggestions/46604530