I just loaded it up against the previous one. In all honesty, I preferred the black, largely because it nicely frames the content in my email client, and that's useful on a larger display (I mostly read email on an iMac) that's predominantly white elsewhere. It also stood out against other messages I receive, which are mostly text-based.
Other observations: in my email client (Apple Mail), the footer test was white and therefore unreadable (against a white background); none of the previous footer links were there (podcast; apps; etc.)
